I use 2 systems. For online note writing the key thing is low friction, so use a real editor you're very familiar with and make the system as simple as possible. I personally use neovim with vimwiki and a plugin called notational-fzf-vim. This makes it very fast to search and very fast to start new notes. A lot of people have a similar system using org-mode in emacs. The main thing is that it works well for you and doesn't introduce friction and slow you down.
The vast majority of my note-taking is in paper notebooks. I personally use a leuchterm notebook, zebra sarasta pens and a system of my own design that is similar to the "bullet journal" system but modified a bit to suit my needs a little better. I personally find if I'm attending a meeting, taking notes in a paper journal makes me more 'present' and able to concentrate than using a laptop (even though I've been using computers for ever, can touchtype fluently etc). I also find a paper system helps me with recall compared with typing. Obviously a lot of people prefer a digital format. I use a completely standard pen and notebook so all my notes and notebooks look exactly the same, and put every note on a separate page (eg if I have several meetings the notes each start on a separate page). I have also find this combination works well for ocr when I need to, so it's very easy for me to just take a snapshot of a page in my notebook if I need to send it to someone, put it in something like evernote or OneNote or whatever.
I second the comments a few people have made around retyping/rewriting notes etc. I find "curation" activities of this kind incredibly helpful as they are a forcing function to think again about things, helping me with recall and conceptual clarity. So would strongly recommend you try this.
//Couple of updates about process