I recently started making small handwritten TODO lists that I keep in my pocket. It has significantly improved my productivity. Every morning while I'm getting ready, I usually think of about seven or eight things I really want to get done that day, and if I'm lucky, I'll actually do one or two. With this method I find I'm getting about four or five things done.

I find that the act of actually handwriting the TODO lists helps solidify exactly what needs to be done and in what order. Keeping it in my pocket is also a nice mnemonic. I'm always feeling the paper when I reach for my wallet or something so I don't forget. I keep a pen in my pocket too so I can add stuff to the list and cross things off as I finish, which is really satisfying. It's also useful for capturing various little thoughts, observations, project ideas, and other things that float into my mind at random points.

It works better than task management apps or calendar reminders on my phone. It's a pain to configure those sorts of things and I actively try to avoid staring at my phone too much. Sometimes the old-fashioned approaches are the best.