Many answers to this one... here's my two cents.
1) Get rid of debt and don't carry any. Debt=slavery and as long as you have debt you cannot be self-sufficient IMO.
2) Learn the skills your great grandfather probably took for granted. Gardening, hunting, fishing, building - never hurts to know how to do these things.
3) Leverage technology so that it is useful to you and not wasteful. Things like Solar power generators, etc are very useful to the self-sufficient as they have no recurring fees to tie you to the world so to speak and provide you with the same flow of electricity that those who prefer to pay monthly power bills get. Solar furnaces, also a good idea.
4) Own your property outright - no mortgage payments. True property ownership is, of course, an illusion which is easily proven by not paying your property tax and watching the government take 'your' property away from you but as long as the bank also can make a claim you are not in a entirely good position.
but then this also depends on the definition of 'self-sufficient' - some assume this means you earn your own money and pay your own rent, to others it means something more, a lot more. To me it means everything and I strive everyday to come up with ways to make me less dependent on society and government and more reliant on myself.