Bedroom design help!?

Im trying to figure out the best way to redecorate my bedroom. Im a full time student and am stuck at home with my parents for the time being and I want my room to represent a 21 year old women, not a 14 year old girl. My biggest problem is that harry potters bedroom under the stairs is bigger than mine. I know I want to paint it red and cream and incorporate music and Paris. Thanks for all the advice, its greatly appreciated!