I have a thing for personalizing kid rooms. More than any other room of the house I feel like this is the one where I can truly get creative and try anything. The pictures below used to be my kids' bedrooms.
The fantasy bedroom was created by freehanding the castle using one of their toys for my model and by projecting the dragon (found on the internet) onto the wall using a small craft projecter (one of the best Christmas presents EVER!). After painting, the pictures were outlined with permanent marker. A warning: yes, the marker can be covered by primer later but it will take at least three coats of it as I learned when we sold this house and I had to repaint this room something a lot more boring.
The jungle room was orginally painted for my sons but soon after finishing it I found out I was pregnant (with a girl) and we moved the boys into the bigger room where I made their castle. In the jungle room the giraffes and the elephant were projected onto the wall and I traced with pencil (because I'm TERRIBLE at drawing living creatures) but then I freehanded the plants. Plants are very forgiving and it's really hard to get them wrong. For the plant styles I used my favorites from an idea I'd seen in a magazine. This room we left as is when we sold the house and the family moving in had a two year old little boy who was going to live in it.
The lamp was originally all white and I got it for about $10. I painted the black stripes on it and then watered down some orange craft paint to give it a wash.
In June I'm moving again, one way or another, and I will be painting bedrooms again. I'm thinking a forest bedroom for Glenn (kind of like the Brother Bear movie-ish), a pretty green room with butterflies and fairies outlined in purple and blue for Erin, and maybe pirates for Joe (treasure map, etc). The last one I'm not entirely sure of just yet (he doesn't have really strong feelings on any particular style) so I'll probably paint the other two first and let him think about it. Have any ideas?