To apply wallpaper, sand away blemishes in the wall, apply an oil-based primer, measure and cut the wallpaper, wet the wallpaper, and hang it on the wall, as DIY Network recommends. After hanging wallpaper, smooth out any wrinkles and press the seams together.
The first step to applying wallpaper is to prepare the area, DIY Network advises. Sand down any bumps, and fill in divots with drywall compound. Paint the walls with an oil-based primer to help the wallpaper adhere to the walls.
The next step is to cut and apply the wallpaper, DIY Network explains. Measure a length of wallpaper 6 inches longer than the wall, and add an extra 1/2 inch for the inside corners at the lap seam. Fill up the wallpaper tray with lukewarm water, and immerse the piece of cut paper into the water for 15 seconds. Fold the ends of the piece paste-side down to the middle to distribute and activate the paste. Carry it to the wall, and hang it.
Finally, smooth out the wallpaper and trim the edges, recommends DIY Network. Using a broad knife, smooth the wallpaper from the top to the bottom, removing any wrinkles and excess adhesive. Use a utility knife to trim the top and bottom of the wallpaper, aligning it with the wall.