I know I tried to paint a TPI Ice Coke Bear that I bought... it came out pretty nicely until I lit it up. I might try stripping it again and repainting it next year.
Been there, done that. I think there are three tricks to getting a good paint job.
1. Make sure the blow mold is clean, clean, clean. No residue from the stripper, no dirt or dust, no soap scum.
2. Paint it while it's illuminated. Takes away the guesswork.
3. Light coats. You can always go back and add more, but you can't remove drips when you put on too much.
Well, there's 2 more cents!
My motto is that if it doesn't move, put lights on it. If it does move, sneak up behind it and put lights on it anyways.
(Motto borrowed from Bob Van Streader, cuz it just made me laugh!)
My stained glass shop: http://beyond-the-looking-glass.com