Hanging Wallpaper: Hanging and Trimming
Before papering, use a straightedge, a level, and a pencil to mark top to bottom where each strip will fit on the walls.
Carry the first glued and booked strip to the wall, and unfold the upper half of the strip. Align one of the edges of the strip with the appropriate pencil line, and place the top edge so that it slightly overlaps the ceiling or, as here, the base of the crown molding. Smooth the paper against the wall with your hands, moving sideways and downward until you reach the midpoint. Unfold, and affix the bottom half.
A 4-inch allowance added to the length of each strip allows for irregular edges along the ceiling or baseboard. Using a wide scraper as a straightedge, trim the edges with a utility knife.
Flatten any wrinkles with a plastic smoother.