Originally posted here by cwk9

3. Borrow my friend’s hunten rifle and fire it in the air while yelling. (i.e the international sigh for get off my land)

I decide on three. Long story short they never came back.
My father still does that, everytime someone comes up to our house selling something, he opens the door with his 12 guage Remington shotgun in his hand, it seems to work, haven't seen any door-to-door people since last year.