One of the drills that I like for passing is the pepper passing drill, because you get a lot of quick passes and need to keep the speed of the drill going.
In this drill one person stands on the ice with three or four people making somewhat of a semi circle around them. The person across from the three or four players starts off with a ring and passes it to the person on the one end, and the ring is passed back to them. It keeps going with passes to all the players, and after a couple of passes to each person you switch who is the person starting with the ring.
This drill is good for having to think quickly when you get the ring on your stick, and it helps you make faster passes in a repetitive movement.