The Beracha of Shehechiyanu was instituted for uncommon or periodical occurrences and experiences, such as holidays and their mitzvot, fruits in their new season, major purchases, and exciting news.
Shehecheyanu for new fruit
- Chazal enacted Brachat Shehecheyanu for eating a new fruit because it brings a person happiness and should praise Hashem for the opportunity.  Even if you don’t feel a happiness for eating a new fruit, one still should make the Bracha (as we assume that he’s happy inside, even if he doesn’t express this externally). 
When to make the Bracha
- According to some it is preferable to say Shehecheyanu before the Bracha on the fruit, however, the minhag is to make the Bracha on the food and then the Shehecheyanu. 
- One only makes a bracha on the first time one eats the fruit (that year). 
- If one forgot to make the Bracha before eating, one may make it as long as one has not finish eating; however once one finished, one can’t make a Shehecheyanu on that fruit. 
Which fruit require Shehecheyanu?
- One only makes a Bracha on fruits that grow yearly, however, fruits that grow all year round don’t require a Shehecheyanu. Therefore, some poskim hold that one doesn't recite a bracha on new fruit nowadays since all types of fruits are available all year round.
- The minhag is that one doesn't make a Shehecheyanu on vegetables or upon a nice smell (Besamim). Sephardim hold that one can recite Shehecheyanu on vegetables that are available only seasonally.
- Fruit that’s available in the marketplace all year round (because of the refrigeration and transportation) do not require Shehecheyanu, (however it’s preferable to cover it with a Shehecheyanu from another fruit if possible.) Therefore, it isn't the minhag to recite Shehecheyanu on vegetables since they are generally available all year.
- The following fruit don’t require a Shehecheyanu: banana, lemon, lettuce, cabbage, potato, carrot, onion, pear, dates, sunflower seeds, pumpkin seeds, nuts, peanuts, almonds, olives, mushrooms, wine, and grape juice.
- The Sefer Vezot HaBracha writes that the general list of fruits in Israel that are considered not available all year round and deserve a Shehecheyanu includes the following (however, in America, it’s very possible that some of these are available all year round; this is from 2009, when the sefer was reprinted but might not apply now): avocado, watermelon, peach, cherry, quince, mango, apricot, grapes, strawberry, plum, cactus fruit, and raspberry.
- There is a dispute whether or not one can recite Shehechiyanu on carobs (buxar) since they don't appear to be a new fruit. If one gets particular enjoyment for seeing the new carobs in their season one can recite the bracha.
- One does not recite sheheheyanu on a new fruit if its taste is not enjoyable. 
- One cannot recite a shehechiyanu for two types of the same fruit. Additionally, if one type of fruit is commonly found all year and one isn't, neither receive a shehechiyanu. For example, all types of grapefruit or clementines are considered one type for the purposes of shehechiyanu. Additionally, one should not recite shehechiyanu for Jaffe oranges and Valencia oranges since they're both in the same category as oranges. The same is true of Anna apples and Chermon apples.
Hybrid Fruits (Kilayim)
- Shehecheyanu is not recited on a fruit that was grown through the violation of kilayim (mixing species).
Shehecheyanu for new vegetables
- There is a disagreement regarding whether or not Shehecheyanu should be said on seasonal vegetables. 
Shehecheyanu for new clothes or other items
- If one builds a new house or buys or receives a new vessel or clothing of significance a Shehecheyanu is required. 
- If one purchases insignificant clothing such as undershirts, sweaters, white-shirts, pajamas, and socks, no Bracha is required. 
- In general, shoes don’t require a Bracha of Shehecheyanu; however, expensive and important shoes can require a Bracha, unless they are made from leather in which case there’s a dispute if the Bracha should be made. 
- Important clothing such as a suit, tuxedo, expensive hat, or shtriemel can deserve a Shehecheyanu if the clothing brings joy to a person. Some have the minhag not to make Shehecheyanu on clothing at all. 
- There’s a dispute whether one can make a Bracha for buying new Seforim (religious books); however, if one receives important Seforim as a present one can make a Shehecheyanu. 
- If multiple people purchase new garments, each should recite Shehecheyanu on their own, rather than have one recite it on behalf of everyone. 
If it benefits others
- If the new house, vessel, or clothing also benefit others with a physical benefit, then one should make HaTov VeHaMeitiv, however, if it’s only beneficial to oneself, make Shehecheyanu.
- For buying a new and significant household item (such as air-conditioning or cabinets) the minhag is not to make a HaTov VeHaMeitiv; however, the one who makes the Bracha has nothing to lose.
- One should make a Shehecheyanu upon buying a new car unless one's family will also use it in which case one should make HaTov VeHaMeitiv.
- If a boy gives an engagement ring to a girl one of them should recite a Hatov Vehameitiv to exempt both of them since they both benefit with this gift and agreement to get married.
- If a person received a large gift he should recite shehechiyanu. However, if he's poor and receiving the gift as tzedaka is embarrassing he does not recite a bracha.
When to make Shehecheyanu
- The halacha is that the Bracha should be made at the time of buying the new clothing; however, the minhag is to make the Bracha when wearing the clothing. 
Seeing a friend
- If one saw a friend for the first time in at least 30 days then one should say Shehecheyanu. This applies even if one has received a letter from the friend. 
- If one saw a friend for the first time in at least 12 months then one should say a beracha of Mechaye Metim instead of Shehecheyanu, but if one had received a letter or heard about how the friend is doing then only Shehecheyanu should be said. 
- Some do not have the custom to say Shehecheyanu and Mechaye Metim on friends whom they have not seen in a long time. 
Shehechiyanu for Mitzvot
- Any mitzvah which has a fixed time and only comes irregularly deserves a Shehechiyanu. This includes milah and pidyon haben. However, the minhag Ashkenazim isn't to make Shehechiyanu at the milah.
- Any mitzvah which has a fixed time every year and isn't common deserves a Shehechiyanu. This includes shofar, sukkah, lulav, chanuka candles, and purim.
- Some have the minhag to recite a bracha whenever they do the mitzvah the first time such as lighting Shabbat candles for the first time, going to mikveh the first time, or putting on Tefillin the first time (if it's at the age of 13 or above). Most poskim disagree with that minhag. Some poskim recommend that when putting on tefillin for the first time, one should recite the shehecheyanu on a new fruit or a new tallit.
- On the day of the Bar or Bat Mitzvah a person should try to get a new fruit in order to recite a Shechiyanu and have in mind to exempt the fact that today he is entering into the yoke of mitzvot.
- Mishna Brurah 225:10
- VeZot HaBracha (18:1, pg 159) in name of Rav Elyashiv and Rav Chaim Kanievsky. Rav Schachter (Inyanei Rosh Hashana, min 25-29) suggests that really we shouldn't recite the bracha for a new fruit that we're not excited about seeing or eating it in its new season, especially when it is a strange fruit imported from far away.
- Halachot Ketanot 1:236 writes that perhaps it is best to recite Shehechiyanu before the bracha on the food so that Shechiyanu isn't an interruption between the bracha and eating. However, he concludes that he should say it earlier like we do for Lulav and Shofar that first we recite the Bracha of the Mitzvah and then the Shehechiyanu. Kaf Hachaim 225:24 cites both opinions but concludes that the minhag is like the Halachot Ketanot to recite the Shehechiyanu after. Halacha Brurah 225:24 and Yalkut Yosef 225:9 agree. Mishna Brurah 225:11 writes that it’s preferable to say Shehecheyanu first in order not to make an interruption between the Bracha and eating. However, Vezot HaBracha (pg 159) writes that the minhag is to make the Bracha on the fruit first.
- Mishna Brurah 225:13
- Yakut Yosef 225:8
- Mishna Brurah 225:13, Halacha Brurah 225:23, Sh"t Besel Chachma 5:27, Vezot HaBracha (pg 160) quoting Rav Elyashiv
- Shulchan Aruch O.C. 225:6, Yalkut Yosef 225:11
- Rav Hershel Schachter on yutorah (Ketubot 57 min 52-4)
- Kitzur Shulchan Aruch 59:17
- Yalkut Yosef 225, Halacha Brurah 225:42
- Vezot HaBracha (pg 161), Halacha Brurah 225:42
- Halacha Brurah 225:42
- Vezot HaBracha (pg 162-3)
- Vezot Habracha p. 163
- Halacha Berura, page 368
- I made a mistake and apologize for dismissing the question. Shulchan Aruch O.C. 225:4 writes that for shehechiyanu that two types of fruits that are similar still require two shehechiyanu's. Mishna Brurah 225:18 writes that if they have different names or tastes they are separate. But he quotes Gra who argues with Shulchan Aruch and holds that if they're one type they're one bracha even if they taste different and have slightly different names. Mishna Brurah isn't clear about if he follows this Gra. Kaf Hachaim 225:34 is concerned for the Gra and quotes the Chida and Maamer Mordechai who agree. He concludes that we wouldn't recite a bracha on each one separately because of safek brachot lehakel. In 225:36 he writes that even if they look different, have different names and tastes, still for shehechiyanu they are all one. Vezos habracha p. 162 quotes R Elyashiv and R Sheinberg that Anna Apple (type they sell in Israel) isn't another type of apple compared to other types and doesn't get a shehechiyanu. p. 164 he writes that different types of oranges like ולנסיה and שמוטי types aren't two species. He says the same for all types of clementines, apples, and grapefruits.
- Igros Moshe OC 2:58 and Kaf Hachaim 225:26. Kaf Hachaim quotes a dispute between the Halachot Ketanot 1:60 and Yavetz 1:63 if someone can recite Shehechiyanu on a fruit that was planted through kilayim since it was created in sin. He concludes that the minhag isn't to recite Shehechiyanu and one should follow that to avoid the dispute.
- BI"H, Re'eh, 12 and Shulchan Aruch 225:6 say that shehecheyanu should be said while the Kitzur Shulchan Aruch 59:17 rules according to the custom to refrain from shehecheyanu on seasonal vegetables.
- S”A 223:3
- Mishna Brurah 223:13 explains that some say that there is no bracha for buying new sefarim since halachically one doesn't benefit from mitzvot. He quotes others who say that if one was endeavoring to get a certain sefer and got it, thereby bringing him joy, one should recite the Shehecheyanu. See also Piskei Teshuvot 223:6 and Rivivot Efraim 8:548(6)
- Vezot HaBracha (pg 169)
- Piskei Teshuvot 223:6.
- Rav Herschel Schachter (min 30) quoted Rav Soloveitchik as holding that nowadays one shouldn’t say Shehecheyanu even on a new suit because it’s common to own multiple pairs and buy them frequently.
- Rabbi Yacov Kermaier writes that for someone who buys a suit once a year one should make a Shehecheyanu and if it’s more routine than that one doesn’t make the Bracha.  writes that according to those who don’t make a Shehecheyanu on a new suit they would be able to buy it during the three weeks but it’s not preferable if it gives you some joy.
- However, Kitzur Shulchan Aruch Sefardi 47:6 writes that the minhag is to make Shehecheyanu on a new suit. Or Letzion (vol 3, pg 236) holds that one should make Shehecheyanu on a suit. Piskei Teshuvot 223:6, Halachically Speaking (vol 4, issue 3, pg 7), and Rivevot Efraim 6:308(3), 8:136 agree.
- Brachot Shir VeHaShevach 2:4 pg 36 writes that even a rich person who buys suits like he buys shirts and isn’t very excited from them should make the Bracha of Shehecheyanu because it gives him satisfaction to wear clothing that is presentable. However, if to him it’s like buying new socks then one should not make a Bracha. On pg 235 he quotes Sh”t Divrei Chachamim chap 15 #201 who quotes Rav Moshe Feinstein that one makes Shehecheyanu on an expensive suit.
- However, Aseh Lecha Rav (vol 8 pg 60) writes that one should make a Shehecheyanu on it even if one isn’t happy because most people would be happy with it.
- Kitzur Shulchan Aruch 59:11 writes that one shouldn't say a Shehecheyanu upon buying new Seforim. Mishna Brurah 223:17 writes that if one receives important Seforim as a present one can make a Shehecheyanu. Vezot HaBracha (pg 167) agrees.
- Sh"t Rivivot Ephraim 1:23:2
- Shulchan Aruch O.C. 223:5, Mishna Brurah 223:21
- Piskei Teshuvot 223:6
- Sh"t Rivevot Efraim 1:375 in the name of Rav Moshe Feinstein
- Rav Hershel Schachter (Brachot Shiur 114 beginning)
- Shulchan Aruch O.C. 223:5 rules like the Rosh who holds that for receiving a gift one should recite hatov vehameitiv since it is good for both the giver and recipient. Gra 223:14 s.v. shehiy disputes this point and holds that a shehechiyanu should be recited. Mishna Brurah 223:21 and Halacha Brurah 223:27 agree to recite shehechiyanu.
- Mishna Brurah 223:20, Kaf Hachaim 223:42, Halacha Brurah 223:27
- S”A 223:4, Mishna Brurah 223:17, and Vezot HaBracha (pg 167) write that the halacha is that the Bracha should be made when a person buys the clothing. However, Piskei Teshuvot 223:7 emphasizes that the minhag is to make the Bracha when one first wears it.
- Kitzur Shulchan Aruch 59:20
- Kitzur Shulchan Aruch 59:20
- BI"H, Ekev, 14
- Rambam Brachot 11:9
- Shulchan Aruch and Rama YD 265:7
- Rambam Brachot 11:9
- Rashi Menachot 75b s.v. haya explains that a kohen recites shehechiyanu the first time he ever brings a mincha. Based on this, the Rokeach 371 writes that when performing any mitzva for the first time, one should recite shehecheyanu. Rambam (Pe'er Hador Teshuva 49) agrees. Therefore, the Rama YD 28:2 writes that one recites a shehechiyanu when one does the mitzvah of kisuy hadam the first time in one's life.
Tzitz Eliezer (13:24) writes that this discussion is only relevant if one didn't begin prior to becoming bar mitzva for tefillin or prior to getting married for lighting Shabbat candles. If one began earlier, he certainly would not recite shehecheyanu. Nitei Gavriel Bar Mitzvah 37:6 and Lehoros Nassan 2:9 agree
- Tosfot 75b s.v. haya (as well as Tosafot Berachot 37b s.v. haya) explains that shehechiyanu is only for a mitzvah that happens at a certain time during the year. Accordingly, the Shach 28:5, argues on the Rama and says that we follow Tosafot. Rav Schachter (Brachot Shiur 69) explained that we follow the Shach. Kaf Hachaim 2:22, Yabea Omer 4:50:5, and Yalkut Yosef Dinei Chinuch Katan pg. 47 also say that the custom is not to recite shehecheyanu for wearing tefillin for the first time
- Biur Halacha OC 22 s.v. koneh, Yechave Daat 2:31, Yalkut Yosef Dinei Chinuch Katan pg. 47
- Kaf HaChaim 225:12 and Ben Ish Chai Reeh 17 say that a bar mitzvah boy should wear a new shirt or eat a new fruit on the day he becomes bar mitzvah'ed and have in mind with the Shehechiyanu that it should also cover his new acceptance of mitzvot. See the Tefillin Page.