How should i decorate my bedroom to make it look nicer? & less childish?

http://www.wakeupfrankie.com/Decorating+Tips/ this web site might help i know i love it and im almost 20.and you all so might like wallpaperfromthe70s.com. and try wall murals there fun! try doing the in side of the shelf's with some crazy print wall paper and do the out sid one soled color, like zebra print on the in side and pink/green/any color you like.