Light coat = less chance of running, but personally found taking a coat to the brink of running meant the laqure sat better than if it was to light which seemed to result in orange peel effect??

Guessing as Twins says, get enough on but not to much.

I also found clingfilm ideal for wrapping the tyres then tape the edges up by the rim and use a hair dryer to shrink the film to a snug fit. Quick and easy.