DIY Washi Tape House from Poppinette. This is such an easy and cute DIY for a kid’s room. A Personal Experience Tip: Try a small piece of tape in an inconspiculous place to make sure it doesn’t rip off your paint.
DIY Washi Tape Car Track from Le Jardin de Juliette here. In one of the comments was a question about the tape harming the floor. I’d personally try all the tapes out on a small inconspicuous place to see what happens.