Blind play is very difficult and there are several reasons to do it, mainly to tell people to leave your blinds the fuck alone.

Anyway I actually don't defend much from the SB, but when you do you really have to raise in order to force out the BB. I like to have decent hands here, since it is getting expensive to play them and you are in bad position.

In the BB I defend alot, I mainly call in order to keep it relatively cheap and see how the flop looks. I play alot of hands, but will discard garbage most of the time (72, 82, J3, Q4 etc are not worth defending). Great hands are medium small connectors or 1 gappers suited or not 67, 56, T8, J9 etc... You'll often hit a ragged flop that your stealer will continually try and bluff you off of and these hands can make alot of money.