Google Tasks for basic day-to-day stuff, typically up to a week out from the current day.
For overflow beyond that, I have a Google Sheet that just keeps growing. I categorize activities into their basic category, and then tag them with one of the following: “urgent and important,” “urgent and not important,” “not urgent and important,” or “not urgent and not important.”
What “urgent” means is obvious, but “important” is intentionally vague. Specifically, it’s “important to me and not necessarily anyone else.” It’s a value judgement encapsulating a lot of things. Do I enjoy it? Do I care? Will it help me achieve something? Do I feel happy for having spent time on it? Etc. It’s best used as a quick gut check.
I then order from top to bottom in terms of urgency, and then importance. This way, discipline is pretty much out of the question: I simply pick the top item and get to it, as logic has already dictated that it’s the most urgent item, which by definition has to come first. Beyond abject urgency, items sort themselves by their importance to me, therefore also removing discipline (I don’t need to be disciplined in order to work on things that are important to me).
This way, it’s kind of a self solving system, as problems identify themselves quickly and naturally. If I’m always stuck in one of the “urgent” quadrants, I need to reduce my workload so that I can do more of what’s important to me. And if I’m spending a lot of my time in one of the “not important” quadrants — why? Clearly something needs to change.
The sweet spot is “not urgent and important.” That’s where I want to spend as much time as possible.
I also have fields for things like “next action,” “sub-steps,” “what’s blocking it,” etc. Plus fields for tracking progress of each sub-step (not yet started, in progress, wait, finished, etc).
I use this system for everything — basic to-do’s, app ideas, whatever. It requires a decent amount of sitting down and organizing things, but that organization process is an important time for self-reflection.
It’s low tech, but like how my best financial system is putting time aside each Sunday to manually log every cent I spent that week, it’s effective in that nothing escapes my brain and I’m consistently forced to self-reflect. No other system for me has stuck.