Some common mistakes to avoid when hanging traditional wallpaper include not properly preparing the walls before hanging the wallpaper, not measuring the wallpaper and cutting it correctly, and not applying the wallpaper adhesive evenly. It's also important to avoid stretching the wallpaper while hanging it, not matching up the pattern correctly, and not allowing enough time for the wallpaper to dry before trimming it.

Learn more from our blog: Common mistakes applying peel and stick wallpaper and how to fix them