Are you using an airbrush or painting by hand? If using an airbrush, thin a little more and turn your pressure down. If by hand, just keep smoothing with your brush. When I painted everything by hand I would change brushes frequently to prevent them from gumming up causing me to lose a little control of paint/paint flow.

I agree with brandydoguk. When using cans,, you tend to shake a lot at first to make sure the paint is well mixed inside. This builds up a lot of pressure. Next time when you shake the can, leave it in a bowl of warm water....... it helps the paint also. Spray on to some paper first and then shoot. I still use cans all the time for priming! and this works for me. I have had the bubbles also. Then when it was dry, I sanded it down and re-sprayed.