The best way is to do it horizontally. If you have a 20' wall, using a level, draw a level line at the 10' height. Then, with a tightly rolled background, start stapling and unrolling the background paper as close as possible to the level line. When you have done the 18', cut the remaining roll off. Then I would staple the bottom center and work my way out with only a few staples. Then on the floor roll out another 18' and cut it off. Take the core or whatever remains on the roll and use it to start rolling the paper up along it's 18' length. It takes a little patience to get the ends to roll under, be a neat as you can because once it is rolled up you need to double stick that 18' of end edge. This roll needs to be pushed against the corner, where the floor and wall meet, often I use a brick to prevent the roll from unrolling. once the double stick is peeled, I stand in the middle of the roll and gently lift it up until it covers the paper on the wall by 2 or 3". Stick the center and with someone holding one end of double stick, smooth out from the center towards that person, then do the other side. I put a few staples in each end to reinforce the double stick.
Good Luck,
Brian
