Dry all paint cups or containers that you'll be putting the paint into thoroughly prior to putting paint into. Never put the paint back into the gallon or pint jar, the ingredients will mix and could spoil the paint. Paint pumps are convenient to use but they expose the paint to the air and that can speed up the process of breaking down the life and quality of the paint. It is always best to pour as you need and throw out what you do not use. It is best to store paint in a cool dry space.