All the best designers have an inspiration board. (Linda Rodin has a huge one on the back of a door.) They're places to put ideas for new lines, sketches, magazine clippings, fabric swatches, you name it.
I am determined to create an entire inspiration wall. Literally, covered with pictures from floor to ceiling. I'm sure my brain would be ten times clearer if I could put everything inside of it on one wall. But then again, my brain is always cluttered.