I keep a WIP folder: "works in process". Some of them are really good ideas, but I don't have the skill, talent, resources, etc. to 'realize' them (make the idea 'real'), so some are destined to stay in that folder. Some of the things in that folder are partial really good ideas, but not enough to create a whole (like a song with a great hook, but nothing else; or a song that needs a lyric, but I could never put a correct one together).
Sometimes I go back and resurrect older work, after gaining new knowledge and tools...I have a couple that I'm working on right now...they are very good concepts, but have been waiting for RT's or other tools to get them from 'the idea in my mind' to 'that sounds pretty good!'.

I agree that it is easy to sketch...there are so many wonderful combinations of music/words/ideas that one could spin up. My philosophy is that I need to just focus on a few, apply myself to making them into creations that I really like, and accept the fact that not all the 'great ideas' will emerge as finished works--just some of them!

Windows 11, Intel Core i5-8600T 2.3Ghz, 16 gig ram, BIAB 2025 MegaPak, SampleTank 4, Keystation49 Kybd, Neewer NW-800 mic