I used to do that with sheets of A4 paper. Eventually, I had a "master sheet" with a list of projects and ideas that I was working on or thinking about. With separate sheet(s) for details.
But I found it frustrating when I was away from those sheets and wanted to update them. So I switched to a mindmapping app called MindMup. Which I learnt to rely on. Especially as it allows collaboration with colleagues.
Since retiring, I stopped my MindMup subscription. And I really missed it at first. But I soon found Gitmind which gives me back all that I lost. Plus a whole lot more.
!BBH
It's one of its cons, you should bring it all the way wherever you go. You can't immediately update them unless you are bringing it.
It's part of the inconvenience haha.
Never going to happen!
When I go out, I take my wallet, phone, and house key. Sometimes a folded bag in my pocket for shopping. As winter approaches, a hat and soon some gloves.
That's all - no clutter. Jack Reacher is my hero! 😀
!BBH
Good for you!