A pencil and a piece of paper, or an organizer from Staples. :-D
If you're an Emacs user, org-mode is very powerful and quite useful as well. It's what I would be using, if I actually had a computer with me everywhere I go that could run it. http://orgmode.org/
If you aren't an emacs user, or are looking for an alternative, Taskwarrior is a quite popular CLI todo list management app, which has a similar (although not as extensive: org is frankly massive) featureset. It has a companion, Timewarrior, which is designed for tracking time and displaying reports. IIRC, this is an org feature as well. Both have significantly better mobile support than Org, so take that as you will. Either way, if you are going to support mobile, you have need to host the files yourself, or use dropbox. https://taskwarrior.org/
Pomodoro and GTD are both popular methodologies, which you can look into if you're interested in that sort of thing (I'm not, but I've heard good things about them both from people who are). They are applicable to just about any tool, including any of the above (yes, that means pencil and paper).
But ultimately, the only wrong way to organize yourself is one that doesn't work for you. So if anything I've listed works, and you want to use it, do. If it doesn't work, throw it away.
It doesn't matter what tools you use, just so long as they help you Get Shit Done (TM).
I've gotten to like Staples' Arc notebooks. They fold over like a spiral notebook, but pages can be moved freely like a 3-ring binder. Downside, instead of holes, sheets have notches in them to keep them attached to the rings that form the binding. This can be problematic sometimes if you keep moving a sheet around a lot, but I typically don't move a sheet more than twice (once to put it w/ related content, again to archive it if I get around to that). And they aren't suitable as pocket notebooks, but I don't consider that a major issue for myself.
But this helps me a lot for pen and paper notebooking. One of my biggest issues with getting a spiral notebook or moleskine-styled notebook is that entries are completely jumbled, organized only by when they were entered. These let me reorder my pages freely as different projects and types of entries are inserted.
The Circa notebooks were my introduction to the concept. Arc is cheaper by a good bit. The rings are slightly different but paper from one will work on the other, maybe not perfectly but functionally.
thanks! yeah the problem I've encountered when using just paper and pencil is that I seem to stick with it for a day or two and then slowly stop... I guess part of that is training myself to be diligent
If you're an Emacs user, org-mode is very powerful and quite useful as well. It's what I would be using, if I actually had a computer with me everywhere I go that could run it. http://orgmode.org/
If you aren't an emacs user, or are looking for an alternative, Taskwarrior is a quite popular CLI todo list management app, which has a similar (although not as extensive: org is frankly massive) featureset. It has a companion, Timewarrior, which is designed for tracking time and displaying reports. IIRC, this is an org feature as well. Both have significantly better mobile support than Org, so take that as you will. Either way, if you are going to support mobile, you have need to host the files yourself, or use dropbox. https://taskwarrior.org/
Pomodoro and GTD are both popular methodologies, which you can look into if you're interested in that sort of thing (I'm not, but I've heard good things about them both from people who are). They are applicable to just about any tool, including any of the above (yes, that means pencil and paper).
But ultimately, the only wrong way to organize yourself is one that doesn't work for you. So if anything I've listed works, and you want to use it, do. If it doesn't work, throw it away.
It doesn't matter what tools you use, just so long as they help you Get Shit Done (TM).