In general for the mitzvot that are time bound and so women are exempt but they may volunteer, there is a major dispute as to whether they can recite the brachot. Rambam ( Hichot Tzitzit 3:9 and Hilchot Sukkah 6:13) holds that since women are exempt from the Mitzvah of [[Tzitzit]] they can't make a Bracha on it. However, the Raavad (Hilchot Tzitzit 3:9) and Tosfot (Eruvin 96a, Rosh Hashanah 33a, Kiddshin 31a s.v. lo mifkadana) quoting Rabbenu Tam argue that even if women are exempt from a mitzvah they may opt to recite the bracha if they want to do the mitzvah. The Maggid Mishna Hilhot Sukkah 6:13 explains the [[Rambam]] as saying that it is impossible to say VeTzivanu if a person is exempt from the mitzvah. Shulchan Aruch Orach Chaim 589:6 follows the [[Rambam]], while the Rama Orach Chaim 17:2 accepts the Rabbenu Tam. What emerges from the halacha is that Ashkenazim hold that women may recite the bracha upon a mitzvah that they are volunteering to do, while according to Sephardim they may not. See [[Chida]] (Birkei Yosef 654:2) who opines that even Sephardim have what to rely upon to follow Rabbenu Tam and Kaf Hachaim Orach Chaim 17:4 who quotes this. Given the dozens of Poskim who rule that a Sephardic woman may recite the beracha and that that was the custom in their communities, Rav Mordechai Lebhar (Magen Avot, Orach Chaim 589:6) writes that women from those communities may continue with their traditions, but others may not, as the Shulchan Aruch rules stringently and we would say Safek Berachot Lehakel.