The next stage will be to hang wallpaper. Purging it of old wallpaper, or peeling paint, putty.
After, you need to crop the wallpaper, and smear the glue, on the wall and on the wallpaper.
Pasted wallpaper. Now, with using of cloth, expels air, to the wallpaper, fit snugly to the wall. And also considering the junction of wallpaper. That's all the work of wallpapering.