Short bio: Computer Scientist, FOSS supporter (read more)
Tux Machines (TM)-specific
Inspired by the work of a guy named mack_guy911, I will show you a handful of extremely beautiful themes and icons sets that you can use in any Unity-flavored Ubuntu or even Gnome 3 installation. We will also learn a little more about tweaking tools that can help you in this task, namely Ubuntu Tweak Tool and Ubuntu Tweak. Yes, those are two different programs. Please, follow me on a tour of beauty.
How to install themes & icons
The process is very simple. Go to gnome-look.org and download anything you find of interest, be they themes or icons or window decorations. In this article, we will focus on the first two. The packages will come zipped or archived as tarballs, so extract them anywhere, until you get to folders containing icon sets and themes.