One of my favourite designers is Swedish-born Hanna Werning. She is an artist, textile designer and printer and has created patterns for the likes of Anna Sui and Ikea. The appeal of her designs lies in their bold shapes and vibrant colours, arranged in dense compositions. Below are some examples of her peel-and-stick wallpaper strips (no glue required!) which adhere to just about any wall surface. In the images towards the bottom you'll see how they can add a dynamic stroke of whimsy to a neutral room.
Some of Hanna's clients: Anna Sui (USA), Beaumonde (UK), Borås Cotton (SE), Boxfresh (UK), Dagmar (SE), Eastpak (BE), ECO-Boråstapeter (SE), IKEA (SE), In The Room (JP), Lagom (UK), Lisen Organics (SE), MC Living (JP), M-One-11 (AUS), Nationalmuseum (SE), Pentagram (UK), Riksutställningar (SE), Rörstrand (SE), Sagaform (SE), Strömma Sweden (SE), Stüssy (USA), Winkreative (UK), Wisconsin Film Festival (USA)