If you want to add some oomph to your painted walls and wallpaper isn't an option, have you considered vinyl art/decals?
I have used them now enough times to know that they are a really nice option for some of my clients because they are not only easy to customize (not just the size but color and direction too), they are easy to install and best of all well priced.
Dezign with a Z has some great decorative decalz! Here are just a few of my favs...
Ring Circles (set of 16)
3 Deers (Isn't this great? Wonder what my Texas friends would say about this?)
Baroque Headboard (No banging your head on this headboard)
USA Map Chalkboard
As much as I love a professionally designed kids room, I think it's cool when parents understand it's the kids room and they should be able to decorate their room their way. How many times have you heard Interior Designers interviewed as adults and they say that they knew they wanted to be designers when they were a kid and wanted to constantly move the furniture around in their own rooms?
So a safe recommendation to clients who want to unleash their kids creativity in their rooms, is vinyl art/decals.
Some of my most memorable times have been working with my clients kids in helping them choose their theme, art choices and color for their rooms with these decals. The kids LOVE it and I think the parents do too!
They are so easy to hang that most of the times the kids end up placing them where they want and actually hang them all by themselves, better them than me, ha! (By the way, I took the 2 following with my camera phone so not the best resolution).
Say it with words....I like going to Vinyl Attractions when I want a poem, quote or personal message on a wall, their options are ENDLESS for that.
A etched glass look, easy and quick transformation
How sweet is this?
This client wanted a certain saying done and we added it to her breakfast room, she gets compliments on it ALL the time, and that was about 4 years ago.