It’s key of course, to consider the size of your room before you start looking at eye-catching prints. Keep the scale proportionate (a medium size print works on most walls if you’re uncertain): you can use a large print on a small wall but the repeat of the pattern will be reduced, so the effect can be lost. It’s also essential to make sure you change your scale up: make patterns on accessories larger or smaller than those in curtains or wallpaper to create a layered effect; if prints are all the same size, the eye isn’t sure what it’s meant to be focusing on.
Adding layers, such as a photo frame on a wall or objects on side tables is what keeps a room from being dull and feeling empty or flat. It may be that in a small guest cloakroom you choose to create graphic wall art with prints and pictures in bold frames, the black edges lending strong, graphic shapes. If you are using pattern in a small room, keep details such as skirting and ceiling plain to stop it from becoming overwhelming.