I prefer to use two caps. And usually the two caps in the front are usually larger. I like, Kingpin has these caps that have like a solid base on them. There's some that have the base that's around the ring at the top. That kind of tips over sometimes. These are really stable. And the bigger ones I use, basically my solid black, of course, and then I use just the water on the second cap. Just so I can use it for a gray wash. And basically, it depends on how many colors I have to do. I like to set them up where my palette, my blacks are closer to the front and then I separate the colors and put them in back a little bit. I like to actually do lighter colors in the back. So I actually go from dark to light.
Always make sure you shake them up because the ink settles because it's actually particles suspended in a liquid. You're going to always dip back into the black. You're always going to go to the black first, so that keeps it away from everything so you can maintain your distance from your other colors and you don't have any chance of spilling it and getting it everywhere else.