If you are painting and using a roller with a roller tray, here's a trick that makes cleaning the roller tray very easy. Before you put paint into the tray, line the tray with a large single piece of wide aluminum foil and press the foil into the interior of the tray making sure to seal all the edges and corners. You can then use the tray as you normally would. When it comes time to clean up, you take out the foil liner and throw it away and your tray is clean.