One thing I used to do, and maybe could do again, was be a sort of "Gospel mailman" and just drop tracts in letterboxes. In New Zealand, most houses have letterboxes (or mailboxes, as I think you call them in the States) at the end of their front path. It is rare for a house in this country to have the letterbox/mailbox in the front door. During the two years that I lived in the US though, the house my parents rented had a letterbox in the front door, and I think most houses in our neighbourhood were the same. With that, you have to go onto people's properties a lot more and run the risk of being attacked by guard dogs. But in NZ, it's possible to stay on the street (although some letterboxes can be awkwardly positioned up or down shared driveways - my city is a very hilly one). I remember getting to know my local neighbourhood a whole lot better with this method. I would go on outings and target specific streets. Depending on the length of a street, I might do a single long street or several shorter ones.
In more recent times, I have also been leaving tracts on cars. Like you, Annalisa, I put them under a wiper blade. Occasionally, I even hand them directly to people! When I do that, I usually just ask them, "Would you like something to read?" Most of the time, they quite happily take it, and then I wish them a nice day and move on. Sometimes, I have seen them reading it as I've walked away. I usually say a little prayer for them in that case. (Well, I pray for them anyway, but if they're actually reading the tract in that moment, so much the better.) While most people seem to take the tract without any questions, someone will occasionally ask what I'm offering. So I will then say it's a Gospel tract. If they're observant enough, they can also work it out from the title.
Every once in a while, someone will refuse to take a tract from me. So far, they have always been polite about it, although I do remember one woman getting a little irate with me some years ago when I tried to leave a tract in her letterbox (she was just coming home as I left it, I think, so she took it out and gave it back to me). I usually just say, "OK, no worries, have a nice day" and move on. I used to use Chick tracts a lot, but have reservations about some aspects of them now (though I kind of like their latest offering, called Trust the Science!) At the moment I'm favouring tracts I bought some years ago from a guy who no longer sells them. They're in a "business card" format, which makes them ideal for leaving on cars and also for carrying around. They use the KJV and preach the Law, which I like. They do give the Gospel too, although they could be a bit stronger on repentance.
Aside from letterbox drops or leaving them on car windscreens (plus giving them directly to people), I have also sometimes left tracts on the table of a restaurant I went to, left them on buses or left them on an outdoor shop display. A few weeks ago, I actually did give a tract to a beggar, along with a small amount of money (I wasn't that generous with the money, but he looked the sort that might drink, so I didn't want to fuel his habit).
I don't know whether anyone has ever been saved from the tracts I've left, but there are a lot of people in my neighbourhood and general local area who will be without excuse on the last day, and their blood won't be on my hands. I do like the idea of giving a tract to people who come to your door too.
