Jackjet- thats a good tip.... re- air pressure!
I have been using the HOT water method for some time as well, this really makes a world of difference! the heat from the hot water creates much better atomization of the paint. The paint also flows and adheres better as well! therefor less chance of runs as well. Soaking in hot water after a thorough shake is the only way to really achieve a satisfactory finish with cans in my opinion. With this method you can cover more area as well ( much less waste and spatter )