I rarely do. We have a pretty specific sign at the door about door to door solicitation and if the door bell rings, I generally peek out the side window to see who is there before answering. My kid that lives on his own has a key, so he just lets himself in, and the neighbor kid from down the street knocks rather than ring the doorbell, so I always know it's him. So if the doorbell goes, it's usually indicative of the door to door sales types. If I look out the door and it's someone I don't know, with clipboards and the like in hand, I just walk away. If you've read the sign and still ring my doorbell, well....
But when they catch you in your driveway, it's a pain. But, I just say we're not interested.
The Calgary Herald can get really annoying out here, trying to sell. We had one really ignorant guy who pushed it with my husband. My husband is very easy going - very. He ended up yelling at the guy, while the kids and I stood there with eyes the size of saucers.