This is the most important, and the easiest.
Don't be locked into anything. If you create important data, make sure it can be migrated. This can be done on any computer.
Continue to remove until you can remove no more. This requires you to assess what you do on a computer, as apposed to thinking about programs as tasks, and confusing the two. (For example, thinking of Firefox as "the internet")
If you have simplified your system, strive to understand its internals.
Can a human truly feel the beauty of the body without understanding the process by which it works? Surely the physical embodiment of the thing is truly extraordinary, but many times the process by which it functions is even more exquisite.
I like my MP3 player as a physical object. It is well made and beautiful. However, the result of the process (music) has far more beauty, and the process by which it works is even more beautiful. By comparison, I don't care for the physical manifestation at all.
Attempt to know how your computer works. Use transparency as the virtue is is championed to be!