Here's a great short video from the dream master, David Lynch.
In it, he talks about briefly writing your ideas down, putting them into words. I do this with Google Keep; I have lots of notes with short ideas that I surely would have forgotten otherwise. Great for writing quick gags or scenes down.
He also mentions writing scenes onto 70 cards. When you have 70 cards, you have a movie. If you've read Save the Cat you're already familiar with this one. It's a great way to organise your movie, but if you don't have space then you can use Trello. It's a digital corkboard for any project you can imagine, and very flexible. Give it a try!
I'd love to chat with David Lynch. I'm a huge fan of Twin Peaks, and the most recent season was some of the best TV I've seen. A master of his craft and not one to second-guess himself!