Open your paint cans the right way using a paint can opener.
Paint can openers are designed to not damage the rim of your lid when opening the can, this means that your lid will continue to fit properly which will stop your paint from drying out.
Pro tip: Use a Slica to protect your the rim of your paint can when painting. Stopping paint from getting in the rim, you'll be able to fully seal the lid when you put it back on.