No TV, big sticker saying 'no print advertising' on my mailbox, adblocked and jsblocked to the hilt on all computers in the house (I see that as a sanity and a security bonus as well), no physical newspaper. It's as good as clean now, every now and then something slips through and then my first response usually is 'surely people can't be that stupid'.
It sounds like the steps are pretty simple. I live in the suburbs of a US city, and billboards are banned, so unless I go into the city proper (a few times a year) I hardly ever see advertisements.
1) move to the countryside or at least outside a major city, or a place where billboards are banned
