In 7 years of building comps/upgrading them, I have never had a problem walking around in whatever the hell I felt like, not using wrist-straps, and touching whatever I felt like touching. Wrist straps are for the paranoid, those who have already had a bad experience and learned the hard way, and those who like to spend money on super-dorky gear.
Before you do anything, touch a piece of painted metal (like the side of your case). After that, just dont rub a sweater or something. You can put "sensitive" components on cotton if you want, I throw things on my bed all the time. Be wary of it, but dont worry about it so much.
Also, make sure you dont bring magnets anywhere near your comp - specifically the HD - because that will destroy it completely.
You really have little to worry about, as long as you are not completely senseless. The whole barefoot thing might be a decent idea, but again, its just a precaution you dont have to really take.