Managing my daily life with a todo app is the only way I can hope to function any more. In college I used a combination of OneNote and good ol' paper and pencil, and since 2009 I've been using Remember the Milk exclusively. And by that I mean I use it for everything - workout reminders, work, blog post ideas, website bugs, and more. Categorizing, prioritizing, and tracking tasks has become a regular ritual that keeps me accountable for all the different roles that I attempt to fill as an adult.
So why Remember the Milk? Well, it was sort of random when I first picked it up - one of the first things that Google returned to me. Since then I've really grown to love it, though. It categorizes by lists and tags, offers prioritization, supports repeating items, and has an awesome interface. The one lacking is full-fledged project management, so I just crank up Trello in order to track complex, multi-stage projects.
I try to sit down in the evening to come up with a complete picture of the next day, loosely visualizing my schedule and the main goals I want to accomplish. There are always items floating in the 'backlog' that I can pull into the day, otherwise I add new tasks to map what the day will look like. Overloading the day is always a recipe for failure, so I try to be reasonable with my time. If I know that I'll only have two hours of 'me' time after work then I won't add four hour-long projects to the list.
The biggest thing I keep in mind when adding tasks for the day is making sure I know what work is involved. An open-ended task without clear completion criteria will never get closed. In fact, I've gone as far as creating a ticket to do research ahead of time before taking on a questionable ticket, usually assigning for two different days. My wife hates this, but it helps me from falling into a rabbit hole of lost time. I also try to keep my tasks to a small size (less than two hours in length) and prioritize based on when they'll get done, which is not always the true importance.
Things do slip. On busy days I'll have between fifteen and twenty items from my list, so if it's noon and I've only completed three tasks then I know it's time to review the commitment. Better to capture that early and postpone the tasks, keeping the rest of the day on track, then get mired down in a bog of incomplete-able todos. There are also days that I don't make time to the evening before to fill out the full list and I have to spend the morning scrambling, both planning for the day while trying to complete things, which always feels haphazard.
Using a todo app to manage my life is totally worth it in the end. I don't think I could manage being a father and having a full-time job without it, let alone trying to do anything extra on the side. It's also fun to try to apply some agile workflow to this and telling my wife 'no' to last-minute asks, though she's one stakeholder that doesn't take kindly to such responses.