Gather drywall mud, taping knives, mud pan, joint tape, sanding sponge, and primer
Cover floors and protect nearby surfaces
Inspect drywall seams, screws, and damage
Fill screw holes and dents with mud
Apply tape over seams and corners
Spread a thin coat of mud over the tape
Feather the edges with a wider knife
Let the mud dry completely
Apply a second coat over seams and joints
Feather the second coat wider than the first
Let the mud dry completely again
Apply a third thin coat if needed
Fill any remaining low spots or imperfections
Sand the dried mud smooth
Wipe away dust
Prime the walls before painting