Instead of dipping your brush into a gallon can of paint, one of the easiest interior painter tips is to transfer a small amount into a paint pail. Pour about an inch of paint into it. A small amount of paint will stop any drips, dipping your brush in too deep, reduces the weight and expedites cleanup should you accidentally spill the paint.
You can purchase special plastic paint pails that have handles built-in or a metal one. An empty paint can that has its rim removed will also make a good paint pail. You can remove the rim easily using a standard kitchen can opener.