Couple of moves:
(This one's inspired by contact dance) Stand back to back, helps to be similar height. One person bends at the knees, hooks their bum under the other persons and leans forwards so the other person can lie along their back. Now the bottom person can spin the staff in helicopter plane below them, and the top person can spin in helicopter plane above. With a bit of practise you can go back to standing and then swap positions so the bottom person is now on top. Quite easy to whack your partner in the head, but you can do the transition without missing a beat. I call this the helichopter cos I made it up with Bas who is polish and has an interesting was of saying helicopter

Nother one: start facing each other, both spinning helicopters above your heads, so that the end of the staff is passing from left to right in your field of view. At the same time, each take the staff off centre (so the long bit is on the thumb side) in your right hand and pivot rightwards. As you turn, bring the staff down to waist height, and when you are back to back with your partner let the staff carry on moving, so it appears on their left side. Grab the staff that's hopefully appeared on *your* left side, complete the spin and go back to helicoptering
For two person throws, I found it really useful to start out heavily synchronised, with counting and everything. It can be confusing when you throw a staff which is going forwards, and get one in return which is going backwards etc. The simplest thing to do is start out both spinning forwards, with the staffs in your right hands, count to three and throw to the other person. You can then transition btb to have a staff (which is now backwards) in your right hand again, and keep them moving round in a circle. Then start experimenting with different directions, changing the direction of flow, adding pirouettes, more staffs etc. Zero spin throws are nice, where you throw the staff you've caught immediately, so the two of you are almost just keeping two staffs spinning in the same place...
There's a few more nice ones I can't remember at the moment, I'll have a think when I get someone to play with