+1 for wet palette. Makes it so much easier to get good-looking coats of paint on your models. Surely you've heard it before, but the end result of multiple thinner coats is seriously better than a few thick globby ones.
Dedicated ones are probably a good idea, but my buddy and I have been using a tupperware container ~big as your hand with some h20 and a piece of parchment paper inside to great effect. Gotta swap the paper once in a while, but that stuff is cheapo.
I dedicate these deaths to Odin Allfather, Spearshaker, One Eye.
Fleet Shadowmaker - Kabal of the Dying Sun; Cult of Marrow Excised; Coven of Lambent Hunger
Sons of the Last Breath - Chaos Space Marines
Host of Shattered Purity - Chaos Daemons