Brainstorming may be the most enjoyable part of the writing process. The Pre-Writing phase can be neglected at times, and it's a shame. Nothing is better at getting the creative juices flowing than a mind map or random sketches.
Writers are quick to fall in love with the idea of drafting. They think that's what true writing is.
Writing is much more than that.
Make a conscious effort to create the time to daydream and brainstorm provides a foundation for the continuation of a playful mood throughout the writing process.