Are you the type of person who like changes fav color a lot? Or getting tired fast of your room?
It's really expensive puting up new wallpapers and buying new furniture every time you change style/mood/color. But I got a great idea to solve that :)
The trick is too keep all expensive things as neutal as possible. For instant. I once had light grey walls and white furniture. I just had to add 1 color every time i feelt for a change. I switched the bed sheets, curtains, table cloths and some small details, and VOILA! A brand new room!
Today I got white walls and wooden furniture. I prefer a lighter wood. It also make the feel more alive and not so strict to the already plain wall.
This is my bedroom in pink themeI gave mokona a central place in this room since he's white and pink :) Over my bed i got a Macoto poster in frame which got soft pink colors too. I bought two small boxes of glass, one i filled with pink candy. The other i decoreated with some pink springflowers. The details are small, but they still completes the look. Also notice the pink tulips in the kitchen :) The curtains are cheap sheets I bought on sale and turned into curtains with a hem ^^ I got another layer of curtains behind which is white lace (from IKEA) I always let the lace curtain show because it's so pretty! There are two white candle holders in the window tied up with wires. One with a butterfly and one with a dragonfly.
This is my bedroom with red themeThis was December last year. Once again, curtains and small details. My got white sheets with white pattern. I add the nightmare before christmas snow ball under my little christmas tree!
My bedroom with blue themeFound these amazing rococo bed sheets on sale for only €5 (for both!) My Mickey Mouse got a central place on my bed :) I used white cloth for the bedside tables.
My bedroom with green themeI use the same bed sheets at in the pink theme since they were pink x green. But with green curtains instead of pink the room suddenly feels green. I also use green table cloths for our bed side tables :)
My bedroom with summer themeFor this summer I had midsummer theme. Curtains and bed sheets in the same fabric. I bought three sets ans changes one of them to curtains :) They're white with wild summer flowers :)

I'm sorry about the many very low quality pics.... :/