How to Hang Peel-and-Stick Wallpaper Perfectly
1.Prep wall Begin by giving your wall a thorough wipedown and ensuring it is dry. If there are any rough spots, you'll want to sand those, too. Then remove any outlet covers for easy wallpaper hanging. 2. Draw a plumb line Sure, starting wallpaper hanging from a corner and working in might work—if you can be 100% certain your home's walls are exactly straight angles. Since that's often not the case, Rees recommends drawing a plumb line, basically a guideline to ensure your wallpaper is aligned. Using your level, draw a line up the wall exactly 90 degrees from the floor (or baseboarding). ...
Source: housebeautiful.com