To ensure a smooth finish, before applying the wallpaper, clean your wall with a damp cloth to remove any dust or particles.
Start at one side of the wall and measure with a yardstick and a level the width of the paper roll. Mark it with a pencil at the top of the wall and midway down. This will be your guide for the first sheet to hang, Measure the length of the wall from the ceiling. Mark and measure the back of the paper for length.
Cut the wallpaper with a rotary cutter and matt.
Peel back the edges at the top and fold down the back a few inches to reveal the sticky side of the paper. Holding the sticky edge of the paper straight evenly place the paper close the ceiling or crown molding.
Using a wallpaper smoother. smooth across each edge of the paper.
Slowly move down the wall while pulling the paper off of the back of the wallpaper. Use the smoothing tool as you work your way down the wall.
Trim the edges by holding the wallpaper smoother next to the wall as a guide, place an X-Acto knife on the edge and cut across to trim. Using the smoother as a guide will make a straight line while cutting. Repeat across the wall.
Notes
The first thing you need to do is to make sure you have one extra roll of wallpaper for mistakes. You can use a Wallpaper Calculator to get the correct dimensions. I chose a busy pattern so it would hide mistakes or uneven areas.Because this pattern was so forgiving, I overlapped each row by a 1/8 of an inch so there would not be any white sections in between each row of paper. I know with regular wallpaper applications you can paint the wall first to match the paper so the spaces between sheets do not stand out. You can also paint the white spaces to blend them in after the paper is installed.