I was reading this blog post about productivity porn. Probably I can agree that there are many tips about how to be productive in our work, but we can use many of those tips, I think that many of those tips are good enough to make our day very productive. But memory is weak. I recognize that I cannot remember everything that I can do on a day. Mainly once you have many real work projects, side projects or personal projects. So, to make a day productive — mainly if you are a freelancer and nobody is pressuring your work and you must be responsive by your own initiative — you need some tool to track or make you remember your tasks. A calendar like GMail is useful, but as Emacs user, I prefer to use org-mode.
I really cannot mind a day without org-mode making my day more efficient, because I have two main ToDo lists, scheduled and not scheduled with my active projects and some work that I can do without any schedule. Also I can customize the ToDo cycle, where it is defined as ToDo, Test, Verify, QA and Done. Also I can have custom labels, if I want, and I can print a very pretty and friendly version of my ToDo list.
So, I have a good structure of my active projects and those tasks where I can work. Mainly because I usually use the GTD or Getting Things Done task management for my projects. And it is really making me more productive. The main idea behind having a ToDo list, is to not forget anything and never have dead time. That completes my day and my schedule without having a lack of time during my workday, because I always have my tasks organized.