People have different creative processes, but here are a few things that you may want to keep in mind regarding generating ideas.
1. Just like you should set aside time to write, you should set aside time to brainstorm. This is most pertinent to people who, like me, are working on a number of projects and have a pipeline that needs to be maintained. It will be easier for you to work steadily on both aspects of the creative process rather than in spurts and stops.