Well I have tried to create a few more clouds today using a variety of techniques. Most were working OK, but while using Colors! on my NDS I just started to try different things to see if there was a way to speed things up a bit. The one that looks most promising so far is what I’m deeming the “random rim light squiggle” technique.
Basically you just think of an over all shape of the cloud, then go mad with some squiggles that will form the rim lights. After that you use what seems to be standard cloud painting techniques for cumulus clouds of blending, adding a shaded bottom and maybe a few back light colors.
PS- if you own an iphone, ipod touch, or NDS, check out Colors!.