I find the best ideas are the ones that don’t let you sleep. They keep you up asking questions. They unfold. But it’s important to remember that there is no MAGICAL BIG IDEA. (I talk about this a lot when I teach.)
The trick to writing a book is not falling in love; it’s staying in love. Because as enchanted as you are with an idea, a moment will come when it loses its shine, when it stops being exciting and you have to find a way to stay committed.
As for the creative process… I outline pretty heavily when drafting novels. I don’t do that with short stories. I just let myself tell the story, often out loud, usually in the bathtub.
But regardless of format, we all have good days when the story just unspools and we feel like geniuses. And then we have bad days where it’s sort of like lying in a ditch covered by ravenous weasels while your friends lie in their own ditches shouting “I feel ya, buddy!” in solidarity.
Good luck in your work. I hope you stick with it. And keep track of all of your ideas. Even the ones that don’t seem like keepers could spark something extraordinary in the future.