If you're a sloppy manicurist, just paint some white school glue around your nail before your paint job. You can peel off the glue once you've finished, taking the lacquer on your cuticles with it. Image Source: Instagram user hairandnailhacks
Don't just paint over your problems (that won't fix anything). Grab some spackle and a plastic knife to even out holes on your corner or dents in your wall — then add paint on top of your smooth-as-can-be wall.