My bedroom is tiny but I want to use a bold-patterned wallpaper. Nice or nasty?

Nice! A big pattern will have an impact in a small room, but use it on just one wall. Choose the colour of the wallpaper carefully - brights will make a small room feel smaller, and soft colour contrasts in the paper create a sense of space. Balance the overall effect by picking plain colours, subtle textures or small motifs for other furnishings.