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 (Tzitzit 3:9 and 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 (Tzitzit 3:9) and Tosfot (Eruvin 96a, Rosh
Hashana 33a, Kedushin 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 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 17:4 who quotes this.