1) One must ensure not to remove the tefillin shel rosh from the bag until after he has donned the tefillin shel yad. Even though removing the two simultaneously would not violate the rule of אין מעבירין על המצוות, as one does not pass by the shel rosh to take the shel yad, nevertheless, according to Kabbalistic teaching the shel rosh should remain in its bag until after one dons the shel yad.[70]

2) If, for whatever reason, the shel yad and shel rosh are both outside of the bag, one should not begin preparing the shel rosh before donning the shel yad, even if he keeps the shel yad in his hands as he prepares the shel rosh. He should instead don the shel yad and only then take the shel rosh.[71]

3) Once the tefillin shel yad has been tied to the upper arm, one may remove the tefillin shel rosh from the bag, even before he wraps the strap of the shel yad around his arm, though it is customary to wrap the strap of the shel yad seven times around one’s forearm before preparing the shel rosh. Furthermore, one may allow his fellow to begin preparing the shel rosh once he has placed the shel yad on his arm, even if he has yet to fasten it.[72]