Poking holes in the lip of the paint can lid allows paint to drain, so you don't get it everywhere when you hammer the lid back in.
Hammer a nail through the lip of the paint can as many times as you want.
I made holes about ever inch or so all the way around. And when we sealed the can back up we didn't make any extra dribble.
I saw this tip on Pinterest a while ago, but painting the hallway was the first time I remembered to try it.