I find its handy to have business cards with all your contact details on. Not neccessarily saying Free Pest Control etc but something tangible. When you turn up, start by saying, "I'm sorry ro bother you, I know your a busy man" or something along those lines. Offer them your card, very few will refuse to take it, its a "conditioned" thing!
Then say "My name is **** ****** and I do some pest control for ***** ***** down the road/next valley/in the area etc etc (feel free to lie through your teeth at this point, especially if you are away from your own locale!) and I was wondering if