I always need to remind myself of this, especially since becoming a mom and not having a lot of unscheduled time for this part of the process.
Jacqueline Antonovich*Bonus*: always remind yourself that thinking is part of writing. Actual typing of text is just a sliver of writing. So, shower thoughts, walking thoughts, random thoughts in the day about your project *is* writing. Text yourself those thoughts (or get a dictation app)