Concerning masking for lettering and such (was discussed a few days ago; pictures of a FORD pickup tailgate). I saw an article in Hot Rod many years ago which talked about using a brush-on masking agent.

Can't remember what it was called, but I imagine there are different brands on the market. Idea is to brush it on, let dry (it dries to a thick rubbery film), then cut out areas to receive paint with an X-acto knife.

I haven't tried it myself, but the guys in the article thought it was a lot easier to cut evenly with the knife and created sharper edges than masking tape.