We have 2 bathrooms on the upper level of our house, the master bath (which is currently undergoing a mini-transformation) and a bath shared by the kids rooms and the guest room. Here is what we've done with that bathroom:
Shower curtain from Target, valence and café curtain made from a flat sheet from the same collection, it was beyond easy.
Pulled the orange from the shower curtain and used it on the bottom third of the wall, any more than that would have been too much. The decals on the wall were a perfect match in color from the shower curtain. Found them on clearance when Linen's and Things was going out of business.
This is a feature I'm ready to say goodbye to... we have a double vanity, but only 1 sink. So we've used the second half of the vanity as our changing table, hoping our son would get the hint that these things are meant to be done in the bathroom not in his diaper. He's not getting the hint.
I couldn't resist decoupaging the switch plate cover to match the shower curtain.
Very happy with this bathroom, I think it will grow with the kids and I *hope* that the colors keep the flowers from looking too girly.