Johny Thundersbeard does not procrastinate about writing
The best time for planning a book is while you’re doing the dishes.
Letting in the theta waves is a great way to let ideas come to you instead of the other way round. And a great way to let those theta waves take hold is to do some mindless manual labor that puts your body in to automatic mode like exercise, or raking, or working in a trade, or doing the dishes.
In other words, dare to daydream.