Something I've mentioned before on this topic...
Try to make every encounter a really special one. Something fascinating and out of the ordinary. Well off the beaten path. It's an approach to putting people at ease that I learned many years ago while working at Disneyland during my college days.
One way to do that is by using what I've referred to previously as a "novelty" camera. It doesn't need to be a toy. Just something way out of the ordinary that doesn't resemble a digital anything. Something that jumps right out at strangers and engages them before I ever say a word. Doesn't need to be an antique, but those always work really well.
I often use a (truly) near-mint condition 4x5 Crown Graphic that was purchased with that mint condition in mind specifically to attract attention. And boy does it. It's an instant ice-breaker.
I also know the history in detail of both Graflex and my particular sample (right down to the month and year of manufacture), and can regale the potential subject with interesting background facts about the camera, the company, it's use in history (Iwo Jima, the Hindenburg, etc.), and long-ago photographers and subjects (Weegee, Murder Inc., etc.).
After a few minutes of friendly chatting, telling a few fascinating stories and answering questions, I will often open the lens, flip open the GG hood (with a flourish, it makes a great attention-grabbing whoosh of a sound), and hand the camera to them for a look. And the inevitable observation "but it's upside down..." and "No, that's not an electronic viewing screen..."
It's much harder to be afraid of a camera that you've just held in your own hands and looked through with your own eyes.
More often than not I end up having the subject pleading for me to take their picture. And if they are also carrying their own camera I usually end up having to pose for them with my camera as well.
To seal the deal I always offer them my email address (I never ask for theirs, especially if they are female, and I explain why), offer to send them a nice scan, and if they like that a follow-up mounted print (to a safe postal address).
Finally I say, "Hold out your hands" and pop the used flashbulb into them as a souvenir. People just love that. I also always try to let them smell the still-hot bulbs in the Graflite right after firing, and explain how that's a rare and wonderful experience from a bygone era.
Whenever possible I never use an electronic flash for people. Flashbulbs are a really big part of the attention-grabbing mystique. Plus, I like the quality of the slow-burning light much better, both for daylight fill and as a main source at night.
Using this camera and approach I can count on one hand the number of refusals I've ever had.