Felipe asked... "Hi Sebastian, do you have any other suggestion on structural changes that can have massive impact in productivity of knowledge workers?"

Great question. Looking for structural fixes are a great use of time, and they easily help make changes and good behavior without needing to use willpower.

The only downside is there aren't very many universal environmental / structural changes, because everyone's goals and natural workflow are a little bit different. You'll have to spend some time brainstorming them.

There are a few universals though -- mostly related to getting clutter and mess away from you. Cleaning up your workspace, getting rid of clutter, and cleaning up your computer/desktop are near universally good. Beyond that?

I've had tremendous success starting the day on paper instead of on the computer. If that was particularly hard, sometimes I'd leave my laptop at my office and just bring a notebook with me.

If you know you've got a particularly difficult problem you'll want to procrastinate on, and it can be solved solely on paper, then leave your phone and computer at home and head to a cafe with paper and a big block of hours free.

Consider killing your mobile phone. I've gone on and off that over the years... pros and cons. It's nice knowing you can't be interrupted.

If you have a particular kind of work that requires certain different browser windows open, then set them up the exact same way every time. To do sales calls, I have Pipeline Deals, Google Voice, my notes, and my email open in the exact same pattern every time.

If you work out of different environments and slack off on core habits for lack of equipment/gear, then try getting multiple sets of it. A second set of workout clothes doesn't cost much, and if you only occasionally work out more, it's worth it. A second set of vitamins doesn't cost anything at all, because you'll eventually go through all of them. 

What else? Well, it really depends. If you ever catch yourself making excuses, look for a structural fix there. "I don't have my workout clothes" -- get a second or third set of them, and put them everywhere. "My alarm didn't go off" -- always set three alarms.

If something goes wrong multiple times, also look for structural fixes. Computers and phones can deliver all sorts of reminders (the re.minder app for iPhone is good). Sometimes if you keep missing something on the computer, you can write in capital letters on a piece of blank paper "FIRST THINGS FIRST, DO XYZ" and place it on top of your computer. Leave the mail on top of the door handle...

Structural fixes besides anti-clutter are rarely universal, but they're almost always worth the 5-10 minutes of brainstorming. They'll save hours of hassle if you can find to a common problem.