Family Fun on the Cheap
Hang paper airplanes from the ceiling with thick colored thread and map pins.
Tile the wall with vintage storybook or coloring-book pages. (Use wallpaper paste for a permanent application, or removable spray adhesive or tacks for a nonpermanent option.)
Download original art at indiefixx.com, where an ever-changing group of artists put their work online for free.
Cut leaf shapes from fabric, dip them in starch (so they’ll stick), and apply to the wall for a Jungle Book–style alternative to wallpaper. Get inspired by the installations of New York interior designers Maureen Walsh and Trish Andersen at domestic-construction.com (check out the Stitch Project).