tie the room together.
measure one area at a time then cut the wallpaper for that one space. only cut one area at a time.
apply wallpaper paste to the back of the wallpaper and also to the area on the wall you are going to put that strip of paper (only do one section at a time).
work from the bottom up. pressing down as you go by using this tool and follow up with a rag to wipe off any extra paste that comes out from behind the paper. make sure to smooth out any bubbles as you go.
if the edges are not sticking use a paint brush to add a 