My bed: Unfortunately I do not have proper "before" pictures, but you can see my tiny twin size bed frame and the childlike light wood w/ flower design.
My new bed is an actual person size bed, with a tufted white velvet headboard and simple white bedding with black accents.
We kept the small patterned yellow pillow and the yellow drapes from my old room and got these custom Euro shams with a modern yellow and white print (and black trim) made. We repainted the walls gray (after considering printed wallpaper that turned out to be too expensive) to bring out the yellow and tie the black and white together. The modern printed black and white rug was a compromise after not getting the wallpaper- a way to add a cool, fun, grown-up print to the room!
The new bedside table is a simple, modern silver and glass piece that neatly fits into the corner next to my bed.
My desk is a built in, and is perfectly large and functional for my current needs. Before we refinished it, I went through my desk and got rid of things that I've had since I was a kid that I definitely don't need anymore (including a lot of these toys and dolls you see). We also refinished my dresser to match my desk- no need to get a new one!
The new desk is a cool white and is much clearer of all of the other crap. Less cluttered and more grown up! I'm still in the processing of rearranging my belongings and figuring out what to put on my shelves (now that they aren't filled with dolls!)
The shelf unit matching my old bed and bedside table is another piece we got rid of in favor of a simple, black unit that looks sleek and modern.
Finally, the bathroom was pretty easy. We repainted the cabinets black, got new towels, a new rug, some new shelves, and chose a cool metallic gray as an accent!