If you are airbrushing them, don't thin them. That's what caused me to almost give up on them the first time around. I tried again without thinning and they work amazing right out of the bottle.
Clean up is a little tricky. I am too frugal to buy the manufacturer's cleaner/ thinner, so I use 91% alcohol. It takes a little more work to clean them when dry, and I have resorted to using a degreaser like Super Clean to get the really stubborn stuff.