I've always considered myself a mildly self-sufficient girl. I know I can't do EVERYTHING myself, but I try to be pretty ambitious. When I got my first car, my step-dad taught me how to change my own oil. At that time it wasn't that much cheaper to change it yourself (it's about $10 cheaper now), but it was way more convenient because you could do it on your own time!
The best thing about it is that it's incredibly easy to do. I'm NOT a car person...I don't pretend to know what the difference between a 4 cylinder and 6 cylinder engine is, I just know how to unscrew a drain plug. You want to give it a go? There's a great little tutorial online
Just remember that you will get dirty, so don't be like me and wear your favorite pants. Also, make sure there is someone with you. I always go to my dad or step-dad's house to change mine because I don't trust myself to jack the car up right :) I don't want to be stuck under a car all by myself!
Another reminder: PLEASE dispose of the dirty oil properly. Take it to an auto parts store and they'll probably recycle it for you. They're pretty cool like that.
Let me know what self-sufficient things you do!