My 2 cents. I tend to paint figures that are pinned to cork, so that i can get into all of the nook and crannies. However, i will only do that for small model count games, like Malifaux.
Also, if you want to try something new with water effects, you may want to paint them separately. This was you can treat them like two separate projects and if you don't get the results you like with the base, you can keep trying until you find what you like.
This way, your figure itself will not be impacted by extra handling and reattempts at the base.