As somebody who likes to optimise my time - getting up early, getting lots done in the morning, staying on top of emails - I spent most of my life knowing about todo lists, thinking that they were a nice thing to do, but never actually using them.
More recently, I've been using Evernote to keep track of things that I need to do, which has been a massive improvement. Even more recently I've started listening to podcasts, like This Week In Startups, from which amongst other things I've been picking up various small tips about things you can do to help you to be more productive.
Then one evening whilst doing the washing up I listened to this episode of This Week In Startups, where I picked up the idea of doing more things on your phone, particularly todo lists. I was using my Evernote todo list, or sorting out emails, but only whilst using my laptop. Typing things into Evernote or removing them on my phone was not going to work, so I decided to try a todo list app.
I've since installed Todoist on all my devices, and I'm now actively managing the todo list throughout the day. It's been a bit of a revelation. I hadn't realised how much mental clutter you hold onto without realising it, when you have to try to hold your todo list in your head, or just the unconscious unease you feel knowing that things are being left undone.
A todo list is also a simple and highly effective way to formalise your whole day. Todoist allows you to prioritise items too, which I hadn't thought I'd need to do, but is actually really useful. Since the app is dedicated to managing a todo list, it creates absolutely minimal friction to viewing and editing the list. It's really satisfying to tick things off the list.
One more really critical part of being easily able to manage things on your phone, is that you can do them when you think of them. 90% of the times that I remember to do something, it's when i'm nowhere near a computer - since that is when my mind is most free to think of these things. All of these factors added together can result in you getting infinitely more done each day.
Since having this revelation about todo lists, I've started enumerating other categories of random but useful thoughts I have throughout the day. For example I am now maintaining a table of different resources and tools related to software development. The field is so ridiculously rich in languages, frameworks, tools etc that I found this to be another source of mental clutter. Now whenever I come across some new tool or popular library or framework that I have not heard of before, I add it to the table. I've fallen victim to the advertising in This Week In Startups and I'm using Airtable to manage this, instead of Google Sheets.