Let's face it: Tween and teen girls are not all that easy to handle.
At that age, my room was my own private sanctuary where I'd listen to records, flip through Tiger Beat and YM (wow am I dating myself or what?), play around with makeup and my curling iron, gossip with my friends on the phone, have sleepovers and do my homework. More importantly, when I was in a bad mood, I'd be out of my parents' hair.
Tween and teen girls are going through lots of changes, and their tastes can change from boppy boy bands to melancholy Morrissey at the drop of a hat. They want their childhood rooms to grow up and put their own personal stamp on their bedrooms (yes, these personal stamps can change quickly too).
Let go and let them, but avoid massive redecorating costs when their tastes change with the following tips.