Stop overthinking everything. Sometimes, you just have to stop trying to second guess yourself and just start typing (or painting, or playing music, etc.) You can plan and plan, but a lot of creative inspiration comes in the moment. Ideas are forged in the flow of the work, and improvisation is the mother of creativity. So, lay the groundwork and then just get out there and do it.
Inspiration can strike in the most unexpected ways but in my experience, it strikes hardest while I’m actually wrestling with the story in my net, and its important to capture its bounty before it slips back beneath the waves.
Our imaginations are like the sea. So much lurks beneath the surface, seemingly lost to us; but occasionally, a tempestuous thought or sudden fortunate confluence of tides will throw up a gem of an idea.
So, don’t wait for inspiration to strike. Start typing and see what happens.