Dress professionally, but not too fancy.
People are going to judge you, and harshly, based on your appearance. This is especially the case with older people who own the majority of the homes in this country. As long as you’re comfortable, dress as nicely as you can when you’re out door knocking. A polo or button up with chino style pants and comfortable walking shoes is a great combination.
Wear a logo
Wear a shirt with a logo from your company or some other product in the home service space to bring legitimacy to your appearance.
Prepare some leave behinds
Type up a quick note in Microsoft Word that you can leave behind at each home explaining to homeowners why you're out canvassing, some basics about your business and services, and how homeowners can contact you. Print off a bunch of these and keep them in your truck. Leave some space for you to write a little extra handwritten note or hand sign them for an extra personal touch.
Here's an example:
Park in front of the house, and slam your truck door
Your truck is a rolling billboard. Use that to your advantage. Park in a highly visible area and slam your door when you get out of your truck. You can bet that curious neighbors will peek out their windows and see you at the curb!