Use an attachment with a soft brush on your vacuum to remove any dust or cobwebs from the walls. Do not hit the walls with the hard parts of the vacuum or attachments or you may end up leaving a scuff mark.
Place 3 tablespoons of dishwashing detergent in a bucket of warm water. Dip a large soft sponge into the mixture and gently wash any dirt spots that you see on the wall. Do not scrub hard. Rinse your sponge in clean warm water and go over the wall as many times as necessary to remove any residue from the detergent. Dry the area gently with a soft clean towel.
Spray hairspray on any ink spots that you find on the wall. Wipe off with a clean towel that has been dampened with warm water.
Mix 1/2 cup of white vinegar with 1 cup of warm water in a bowl or bucket. Dip a clean rag into the liquid and gently rub over any shiny marks, crayon drawings or food spots that may be on the wall. Dry the area by gently rubbing it with a dry towel or rag.