@DotSauce Agreed. I keep my account honed to my actual friends and a few other people. When people add me and are clearly not into tech or anything I tweet about, I block them. So far, I've stayed spam-free.
I'm not sure if I have to, but I have the impression that these spammers look at other spammers' lists for potential new targets, so keeping myself off those lists is (in my mind) a good move. What's more, it sends a signal to the people at Twitter that this person is no good.
I do think, though, that not reciprocating is probably sufficient. I should've mentioned that I'm also a minimalist and like to keep my lists clean.