Use Cotton Drop Cloths Rather Than Plastic
Spills and spatters happen, regardless of how careful you are. It's a lot easier to prepare for them than to wipe them out of your carpeting or off your wood floor later. All it takes is canvas drop cloths in your work area (a 4-ft. x 15-ft. cloth is about $15). The thick canvas stays in place, so you don't need to tape it, and you can use it to cover any surface. Plastic drop cloths are slippery to walk on or set a ladder on and don't stay in place. Even worse, paint spills on plastic stay wet, and they can end up on your shoes and get tracked through the house. Canvas is slippery on hard floors, so rosin paper (about $10 for 400 sq. ft. at home centers) is better over vinyl, tile and hardwood. Tape the sheets together and to the floor to provide a nonslip surface.
But even with canvas or rosin-paper drop cloths, large spills still need to get wiped up right away or they'll seep through. Clean spills with paper towels or cloth rags. Likewise, if you splatter paint on any other surface, wipe it up immediately.