Saying WaYidaber, and WeHayah Ki Yebi'akha:

The Ben Ish Hai writes that after donning one's Teffilin, they shall recite WaYidaber, and WeHayah Ki Yebi'akha. Some have the same Minhag of reciting it, with Rabenu Taam Teffilin on, although it is not required. If one didn't recite it with Teffilin Rashi on, he is not required to don is Teffilin once more in order to recite it.

The reason for this, is because inside of our Teffilin we have these four Parashaiot: Qadesh Li, Shema, WeHaya Im Shamo'ah, and WeHayah Ki Yebi'akha. Rabenu, and Rashi argue on this matter, however most people simply wear Rashi. Maran holds (S"A, O"H 34) that only people that are famous in their righteousness should wear both. The Ben Ish Hai holds that one must wear both, and at the same time. We follow the opinion, that if you are going to wear both, you shall wear them separately. Although one may wear both simultaneously. Some hold one should only wear both after they get married. Our Minhag is that everyone wears either Rashi and Rabenu Taam, or just Rashi. One only makes a Berakha on Rashi. One is not permitted to bless on Rabenu Taam alone.