An immediate yard fence with a doorbell or similar ringer at the yard gate is a reasonable set up. I don't like to open my door an be face to face to an unknown person so a bell ringer in the yard is helpful.

  A camera capable of clear images aimed at the spot a visitor would hail the house from or at the property entrance is an option.


Petition your township for a non-solicitation ordinance and have it posted then if dealing with a law breaker circumstances are different relating to how you may respond to a given instance, because you may feel threatened or fear harm etc..  

If not prepared to defend ones self either with knowledge or force the probability of victimhood is likely.


A pepper spray nozzle imbedded in the door frame is not out of the question but be careful of accidental discharge LOL