Clean walls that are dingy or yellowed from smoking with TSP or trisodium phosphate. Buy this safe water-soluble salt at most hardware stores. Wear gloves to prevent your hands from drying and if the strong salty smell bothers you, put on safety goggles as well. Mix this with water according to the package and it should take off any filmy residue with ease.
Use baby powder to remove grease stains. Pour a little powder on a clean, soft rag and rub over the greasy spots. Let it stand a few minutes and then wipe it again with a clean cloth. Repeat this as often as needed until all of the grease marks are gone.
Try hair spray for ink marks. Just spray the mark and use a clean soft rag to blot it.
Remove magic marker marks with rubbing alcohol. Wet a cotton ball or cotton pad with the alcohol. Wipe the spots gently and the marker should come right off.
Clean tape marks off the wall with a hairdryer. Put it on low heart and heat up the gooey mess. Gently scrape it with a knife. Just gently scrape the surface of the wall, being very careful not to gouge the paint. You can try to heat the adhesive a bit and then use another piece of tape to pull the sticky stuff off, too.