Holes or Tears ? This is an easy fix if you have matching leftover wallpaper and the design is an overall or large pattern. First, remove the torn area and surrounding paper following the design - the more uneven the design the less the patch will be noticed. Use a sharp single edge razor blade to do this.

Cut a matching design patch from the leftover paper - cover the back with a thin coat of wallpaper paste - apply patch to wall fitting it carefully. Use a damp cloth to smooth the area down.

Seams Openings - Fill a plastic squeeze bottle with wallpaper paste. The spout on the bottle will fit under the edge of the wallpaper seam. One squirt and a little pressure on the spot will quickly eliminate the problem. Wipe any excess with a damp cloth if the paste oozes out when pressure is applied.

Cleaning - Most wall papers are washable, but if yours is not, lightly soiled areas can be cleaned using a borax powder. Wipe it on with a clean cloth (a dry one) then remove the powder with another clean dry cloth.

A slice of rye bread will work as well. Just rub it on the lightly soiled spot. Other breads won't do - it's the gluten in the rye that does the trick.