Water. Gin. Beer. Whatever. I really don't need to be drinking anything in particular. The spit-take is one of my favorite past-times. My last decent one was probably at the Spoon's going away party. I think Darrin got some collateral damage and splashback off of it, and I'm pretty sure he left thinking "heyyy, [extraface] spit on me." I can understand the misconception but no I did not, my man. The spit-take knows no victims; it's intent is purely a whalehole-like spray/stream of liquid sent on a path perpendicular to that of the conversation. Anyone who walks into the stream or cops some peripheral spray is merely along for the ride.
My habit of practicing spit-takes at parties tends to divide the world
into people who think it's extremely funny and endearing, and people
who are really annoyed by it and think I'm a jerk. In case you want to develop your skill set, a few practice drill suggestions, completely gratis:
(1)When you're at a party and someone says something surprising, look sideways and do a spit-take.
(2)When you're at a party and someone says something that's not all that surprising, look sideways and do a spit-take.
(3)If you've just done a spit take and everyone has just about recovered and the storyteller is continuing his tale, wait for another pause and do an additional spit-take.
(4)(*rule of thumb*)Basically, don't ever worry that you're wearing out the joke. More spit-takes = better.