This reminds me of an interview I saw of Tyler Joseph from "twenty-one pilots" where he describes the basic process of song-writing. I can't find the link now,

This reminds me of an interview I saw of Tyler Joseph from "twenty-one pilots" where he describes the basic process of song-writing. I can't find the link now, but the premise is that, it is not enough to just sit around and wait for inspiration to strike - you have to be prepared to take advantage of it. So you practice writing lyrics, practice your instrument or a production technique, even when the immediate output of it seems like crap. You practice until you don't have to think about the thing that you're practicing, so when you're actually "inspired" by something, so to speak, you can just immediately rely on what you've practiced instead of not being able to reach that sound you heard in your head.