F.H.
I just found a "theme" that I liked and then found things on sale that went with it. My daughters room was fairies and my sons was sports themed. Both pretty basic and easy to find decorations for. My daughters room was painted a mauve color about 1/4 way up from the floor and then a cute fairy boarder went around the room. I left the top part the off white that was already there. Same for my sons but it was blue on the bottom and the sports boarder then off white. I had those wooden holders that held different colored plastic baskets of different sizes for their toys. They worked really well and in fact my son at age 8 still has his in his room. I think the biggest thing I learned was to really downsize their toys and only keep what they really love and actively play with. So if I were you I would find a really cute bed set and start with that and build around it. Good luck!