Here's the recommendation I give to students when they ask me this question (it's a common one!): You come up with a brilliant idea, you obsess over it, you Google some info, and on your screen lies your idea, being done by someone else, for the last two years. You’re all too familiar with that sinking feeling in your stomach that follows. You abandon the idea almost immediately after all that excitement and ideation…
I recently bought a Sony Voice Recorder just for talking about the wild ideas. Its amazing how much I was self-editing when jotting notes. Training yourself just to blather into a recorder (I don't use my phone because it felt weird) and then using some text to speech to extract the words later has really been a better workflow for me to get the fleeting thoughts out of my poor memory and into something I can continue to churn.