Mood boards are an essential tool to the fashion design process. Most designers constantly draw inspiration on whatever comes their way, the color of a flower, a painting or color combo seen at an art exhibit, a vintage purse etc. Before creating a collection, a designer likes to create a "mood" for it and anyone of these collected pieces may be used on a mood board, which basically is a collage. Trend bureaus announce future colors we may see and this too gets added to the board, sometimes it is a photograph, a sketch or a piece of fabric found at a flee market. You get the idea. Start a mood board for yourself, if not using it for a collection, then just use it as an expression of your likes and fine-tune your aesthetic.
A digital version of an elaborate mood board is Pinterest, which is an easy way to collect anything.