Why?
After an inspiring talk by Nir Eyal during Mastermind Talks in April 2015 I decided to implement his tips on reducing distractions. Nir is the author of the book Hooked: How to build habit-forming products, which describes how the make something interesting (or somewhat addictive..). To counter-act distractions and have more will-power during the day I took action.

What?
I did this on the desktop on my MacBook, my main distraction is shown below:

My starting point:

After changing some simple points…

Below the result:

How did I do this?
1. Turn off icons on your desktop (use Camouflage http://www.briksoftware.com/products/camouflage/ or script for free in Terminal http://osxdaily.com/2009/09/23/hide-all-desktop-icons-in-mac-os-x/ )
2. Auto-hide your Dock (in my case to the right, System Preferences > Dock)
3. Dark background (in my case with a good quote in white lettering, made the wallpaper myself)
4. Dim or darken your menu-bar (in my case using Menu Eclipse 2, http://www.xybernic.com/index.html )

Work is more focussed, there is only one thing I have to keep in mind.
One sort of downside is that I do tend to have to set an alarm for 30 or 45 minutes, since I don’t look at the time anymore on the right side in the menu-bar.
The menu-bar is darkened and I tend to work longer then my regular 45 minutes per session.