Most productivity advice is written by people who sell productivity advice. The rest of us just need a repeatable system that takes 30 seconds and doesn't fall apart the moment life gets busy.
Here's the routine I use every day with tsks.in. It's not original, it's not sophisticated, but it works.
First thing in the morning, before checking email or social media, I open tsks.in and write down everything that's in my head. Every task, every errand, every thing I'm worried about forgetting. I don't prioritise, I don't organise — I just dump. This takes about two minutes and clears my mind for the day.
After the brain dump, I reorder the list. The most important task goes to the top. The second most important goes second. Everything else stays below. I try to keep no more than five tasks in my active view at a time. If I have more than that, I'm not going to do them all anyway — they're just noise.
I do the top task first. Not the easiest task, not the most urgent task, but the most important task. I don't start the second task until the first one is done. This sounds obvious, but most people bounce between tasks and never finish anything. The satisfaction of checking one box completely is better than half-checking three boxes.
Before I stop working, I review what's left. Anything urgent that didn't get done gets moved to the top for tomorrow. Everything else stays where it is. Then I close the tab and stop thinking about it. The app holds the tasks so I don't have to.
This routine works because it's built on two principles. First, capture everything immediately so nothing lives in your head. Second, do one thing at a time in order of importance. That's it. No GTD, no Eisenhower matrix, no Pomodoro timer. Just a list and the discipline to trust it.