Spread a large drop cloth along the floor to shield it.
Take off all the light switch and plug outlet covers.
Prepare a wall cleaning solution with water and a little bit of trisodium phosphate (TSP). Next, dip a sponge into the solution.
Wring the sponge out well and carefully wipe the walls. Have a rag ready to catch any drips and excess water. Repeat process with clean water.
Remove nails and cover nail holes with spackling or drywall joint compound.
Give the entire wall a light sanding. This ensures a smooth surface. Get rid of dust with a tack cloth.
Caulk any gaps between the wall and baseboards or window and door casings. Use an acrylic latex painter’s caulk.
Wipe finger along the caulk to smooth it out. Use a painter’s tool and rag for tighter areas..
Mask along the horizontal areas of all wall surfaces, especially along baseboards and window and door casings. Sides are optional depending on skill level.
Spot prime in trouble areas, such as heavy stains or repaired holes. It’s best if the prime color is the same or almost the same in color as your existing paint. For complete instructions on how to prime your walls for painting, see this video: Priming Walls for Painting