>>6125428
When you overthink things the most real way to solve it is not to ignore the part of your brain that feels that way, but you don't bend over to every nitpick that pops out from there. There's a good chance your brain wants an answer without a heavy time commitment; references, watching media related to your idea, writing ideas, doing thumbnails (the size of matchbox), color keys, value comps, etc.
Think about steps, and how you handle them or which way you like working best, you don't need to do every example mentioned, but you'll feel confident about what to do next, that's good enough to start a painting, you'll naturally know where to go back if something is not working, and you reduce friction between confusion and answers. In short, what you are doing is not thinking in large, but actually breaking it down into actionable things you can do right now.
PS: If you have to write it down in steps like a recipe, do it, the point is to remember it and then it will become second nature.