Hanging wallpaper is straightforward. You just put the strip on the wall and smooth it down. But the challenge comes when you get to the inside corner.
Don’t Wrap the Corner
When you get to the corner and need less than a whole strip to finish the wall you should cut the paper. If you simply continue around the corner with the same wallpaper strip as on the previous wall it may sag or tear. Measure the distance to the corner and then add 1/2 inch. Cut the strip the width of your measurement. Cut the strip into 2 lengths. Hang the measured strip and it will overlap onto the next wall slightly.
Start the Next Wall Level and Straight
Measure the remaining strip that you cut. Snap a plumb line on the adjacent wall that is the width of the second piece minus 1 inch. Measure this distance from the corner and snap a plumb line. Hang the second strip in alignment with the chalk line.
Align the Edges
The paper is overlapped both ways in the corner. Now cut through both overlaps on one wall getting as close as you can to the corner using a straight edge and a utility knife. Take away the top piece of wallpaper. Now peel away the paper underneath leaving the top layer. Smooth the edges down to be sure they adhere to the wall.
Using professional techniques such as this one when hanging wallpaper will make it look better and it will last longer.