MikeS for the vintage paint win!
I've painted a lot of wheels. Removing the tire makes it a lot easier but taping off or the flashing trick will work, too. Prep is the key. Scuff them up with a 3M pad, clean, prime, and paint. Spray can paint is actually getting a lot better, IMO. The improved nozzles and the paint is better.
Here's one trick I use most of the time with spray cans--I heat some water and pour into a used coffee container or bucket. I immerse the spray can in the hot water for 15 minutes or longer. It tends to deliver a finer spray and a more even pattern.