I use paper. Digital notes are great if you need them to be available everywhere, or edit them time and time again, but paper is still significantly better for me. I keep my recipes in Keep and on my personal website, because I often amend them. However I discovered that printed recipes are much more pleasant to use. Likewise, I'd much rather have a dirty notebook to sketch and write on when I'm working in the garage…
It's just my opinion, but nothing beats paper. I have tried keeping note files on my computer, and I've tried using tablets to jot things down (I have spent so much money trying to get this option to work). Paper just works better. I found that I like to scribble and underline, and draw. I'm just not an organized thinker. Forcing things to be in a list don't work for my thoughts and even drawing on an iPad etc. seems…
I use Goodnotes[1] on my iPad for my notes in which you can do all of that. Works great for me.
But i can understand that a digital solution is not always a better solution for every situation/lifestyle...