For notes, I rely 100% on paper. I don't remember things as well when I type them out, and keeping it on paper gives me a sort of spatial awareness on where to find what I need.
However, with research papers now, I've started to use Mendeley. Imports downloaded pdfs and automatically has author, title etc filled in, can download pdfs from a number of the major publication websites and automatically add to your collection, allows sorting via author, year, etc., allows you to take notes and highlight, and has a search bar that searches through all of the papers you have. It additionally can keep your pdfs synced between computers, creates BibTex entries and I believe can help you find related papers, although I haven't used that function. It's a great way to keep semi-organized, and works a lot better than any file-naming system I've tried.
However, with research papers now, I've started to use Mendeley. Imports downloaded pdfs and automatically has author, title etc filled in, can download pdfs from a number of the major publication websites and automatically add to your collection, allows sorting via author, year, etc., allows you to take notes and highlight, and has a search bar that searches through all of the papers you have. It additionally can keep your pdfs synced between computers, creates BibTex entries and I believe can help you find related papers, although I haven't used that function. It's a great way to keep semi-organized, and works a lot better than any file-naming system I've tried.