Hyde 45161 Plastic Can Pour and Roll, Pour Spout and Roller Grid, Fits 1 Gallon Cans
If there's a better way, it's probably the HYDE way.  Take painting, for example, where painting more easily is often a matter of having the right tool handy.  In this case, it's the HYDE Pour and Roll, a two piece set that allows you to pour paint safely with no spills or simply paint right from the can with a roller.  The set includes a paint-pouring spout that snaps into the inner edge of your paint can eliminating the mess caused by pouring paint.  The lip is equally safe to use with paint, stain and solvents.  Packaged with the pour spout is a roller grid for use with a 4-Inch roller.  The grid attaches to the pour spout in either of two positions - one for use with full paint cans and a second for use with partially empty cans.  The grid removes excess paint from the roller and prepares it for smooth, clean rolling.  It also acts as a brush wipe when dipping paint directly from the can.  There are two versions of this product, one for metal cans and one for plastic cans.