As an Artist and a Professor, in my experience creativity comes from experiences, and your emotional reaction to them.
Keeping a journal, whether it's written or visual, helps keep track of those experiences and the way you felt about them.
For me, music helps to bring those emotions and memories back, and is a great tool to use when you're brainstorming new ideas, regardless of the media.
Let me know if you need any help further developing your creativity.