Photojojo Forums - How to take the foto of 'that stranger'

How to take the foto of 'that stranger' is a topic in Photojojo's forums about being scared to do street photography. There are quite a few tips, which I will think about the next time I go out. There are a few obvious ones like this post by ben-s:

If people do ask questions, be nice to them, and perhaps offer them a free print or an electronic copy. If they're not happy with that, offer to delete the image. I've never had to delete anything yet, but I have sent out a few free prints and a few electronic copies. People are often quite pleased to have a picture of themselves.

And then there are a few tips that user alexlinsker suggests that struck my attention:

Another way is to casually position yourself so one person's body is between you and the person you're photographing. The person "between" you can be a bit off to the side and out of frame.

and my favorite:

... Feet are a big unconscious indicator of where your attention is pointing. Point both your feet away from the person and at something you might be interested in. You can even walk that way after you take the picture.

Also, remember that you need a release if you plan to sell those images, unless of course it's for editorial use!