I think everyone should keep a design file where you put things that inspire you and make you happy. Just start tearing things out of magazines and printing pictures then store them in one file. When you're looking for inspiration you'll have the perfect place to find it.
It's okay if your style or taste changes - my does all the time - just edit your file as you go. Right now I seem to be drawn to older pieces, rooms that have character and a slightly muted palate (can you tell?).