It's really only the one's with a milk like consistency that are really at high risk for spilling and making a big mess. So your inks, washes, and I suspect the new contrast style paint lines. Otherwise, if you are using a dropper bottle or your brush to scoop paint out of a pot to put some on your pallet. Its a very small amount especially if you are doing only one or two figures at a time.
Anyway, I think if you play RPGs as a player or GM there is something very cool about playing with minis you painted. It personalizes the game that much more. And you don't need a hundred colors. The three primary colors, white, black, and if you are living on the edge a couple of shades to pull the details out. I find it to be a very relaxing process.