Jackie,
I have a lot of admiration for you already! That's not an easy thing to do! As an "old" sales guy, I have been trained to approach that kind of situation in the following ways:
1. You don't get paid to sell (tell yourself this), you get paid to knock on doors because eventually, odds are, you'll get a buyer. Figure out what those odds are (i.e. 1 in 100) and what commission you make and divide that commission by the number of "knocks" it takes to get it. That's how you get paid per "knock". Try thinking of your pay as per knock, not per sale and set knock/prospecting goals, not sales goals.
2. I've seen essentially a couple of different techniques for selling business owners. One is to go in with arrogance and total confidence EXPECTING the owner to want to talk to you. ASSUME he/she needs what your selling RIGHT NOW, get your order form ready, tell him your company is going to solve his problems and tell him to approve the paperwork to get the process started.
Some have used this approach in ways that are very aggressive including sweeping all the papers/etc off of the owner's desk while telling him if he doesn't take action now, he'll be out of business!! I don't necessarily advocate that much aggressiveness, but I will say that assumptive selling is powerful and absolutely necessary when a one call close is the order of the day. Confidence sells!
The second approach is the bubbly, excited, confident fun approach. You get yourself in a real positive, fun, upbeat state of mind and walk into the business with a "Hi!!, I am here" greating.
I guess it depends on you and your body type and look. (I don't think gender really matters) If you are large and can look forboding or old like me and can look distinguished or just plain old -- use the arrogant/confident approach, if you are small, naturally bubbly or "cute" use the bubbly/confident approach. The common denominator is confidence however. Assume the sale either way if it's a one call close! Good Luck