There are several different ways to pull rooms together.
As an example, in my bedroom I have used pink, black and white as the main colors. To mix it up a bit I've also used some greens and blues. A lot of my design elements also have circular or wavy elements. Also, some of the artwork and pieces used to decorate are themed around butterflies or birds. Don't forget the importance of light. An above head light will certainly give you a lot of brightness to work with, but some well placed lamps with different colored shades will warm up a room and create a cozy atmosphere.
I also think about the curtains I use. I had black curtains on my windows, but found during the day the light quality in my room was a bit bleak. I decided to go wild and try a pink and white polka dotted fabric. Now when the light filters into my room, it has an ethereal and comforting quality.
There are so many ways you can go with this. Just use your imagination and go for it. Sometimes if you over think it, it gets to be too much. I usually start with the things that I love and it all turns out well in the end. Good luck!