Teenagers always want to have their private room decorated well according to their interests and specific obsession. Girls mostly want their bedroom to be decorated as girly as possible. There are some decorating ideas related to cool tween rooms for girls you can adopt. The first idea is fairy tale room. You can install such wallpaper which represents fairy world in the room. Then, redecorate some furniture so that it looks idyllic. Do not forget to change the curtains and the lighting shade. The next idea is Barbie girl room. Pink is the most important wall color to create Barbie girl room. To make a cozy room, you can install pure white furniture and pastel colored rug. To add some details, you can stick Barbie wall sticker on the wall.