A few years back I read an article in Auto Scale Modeler about laying down perfect paint jobs. The article discussed applying primer coats but focused on the final color. Basically, after applying the first and second coats, there should still be primer shining through (kind of a mottled appearance). The third coat should bring the color to a more uniform appearance, and subsequent coats can be used to deepen the color. The final coat can go on a little thicker than previous coats such that it has a wet appearance - but be careful - too much and you will have a run. Some colors such as silver cover the base/primer coat very well and will not need as many layers.
As previously mentioned, I typically use dowels to hold the rockets while they dry.
I've found that painting can sometimes be the most frustrating part of building (especially since I live in the South with 100% humidity). I'm a bit of a perfectionist and hate it when I get orange peel, cracking, bad mask lines, etc. I always try to learn from a mistake such that my next paint job is even better than the previous. One day I'll get one right.