I was a little bored by everything being one color on the walls though, so instead of a mural I painted a 12" stripe around the room two shades lighter than the wall color.
The hardest part was getting the tape on the wall in a straight line. At first I tried my husband's stick-to-the-wall laser level. But it turns out that since our walls are not exactly flat, the line was warped. So I got out the 4 foot standard level and started penciling in lines and then putting down the tape.
I think the final result is pretty cool and definitely exactly what I was going for.
One tip for those attempting this at home...make sure your tape is just above or below the pencil line you have made. There are a few places on our wall where I was just at the line and the paint didn't cover the pencil and now it won't erase from the wall...but it is too close to the line to try and fix it without making a mess. (you can see an example of that below).