Dust or vacuum the walls first
Protect floors and nearby furniture with towels or drop cloths
Mix warm water with a small amount of mild dish soap
Test the solution on a hidden spot
Use a soft sponge or microfiber cloth
Wring out the cloth well so it is damp, not dripping
Wash the wall from top to bottom in small sections
Rinse with a clean damp cloth
Dry each section with a clean towel
Change the water when it gets dirty
Use a gentle cleaner for stubborn spots
Avoid soaking painted walls
Avoid abrasive scrubbers
Let the walls air-dry completely