If looking for me /who Memento ... will always be me who's online in that guild. Mostly in the evening, maybe today post 19:00.

After you let the pet cast whatever was in his queue, wait for him
to swing his weapon. After he does, hit your FP, then whatever spell
you want to cast, once.

After a few seconds, you'll see your pet begin to cast whatever spell
you queued. While he is casting, hit the 2nd spell you want to cast.
While he is casting the 2nd spell, hit the 3rd spell you want to cast.

Example: lifetap , then FP and powertap , when he starts casting powertap hit another powertap , and an instant lifesteal. If fully buffed and lvl 50 you maybe able to hit 3 powertaps in a row.

One more thing if your pet gets into melee range there is no point in keeping it on passive , the extra melee dps does help you. I only keep passive on permanent if I do any RvR not for PvE .