I just ran into this thread a few moments ago, and quickly read through it all. It would be very nice if this grew into a collection of tips, hints, and just good random chatter on the subject. Thanks for starting it, Nicole.
Here's my input: In the last few days I re-did my website, and in the process realized that my best portraits are not in the portraiture session at all. They are all in my documentary portfolios. I read started to read this thread thinking "Hmm, I really could learn how to photograph children", but for some reason I never count my documentary photography as portraiture. If I did, I'd realize I already know how to photograph children. And adults. And elderly adults. So, if my documentary portraiture counts, here's my 2c:
1 - Before you photograph a person, you should be able to carry out an honest (even if brief) conversation with them. Treat them as human beings, and respect them. Don't deceive them, which includes hidden photography and lies in your conversation (strategic behavior should never rule over ethical behavior - this struck me as true even before studying ethics, but now it's more important than ever). By carrying out a conversation (or even just attempting to. sometimes an honest smile, a look in the eye, and/or a nod of the head go a long way), a bond can start to form. Sometimes this leads to good pictures, sometimes to a good chat, and sometimes both. Sometimes, however it leads to neither. Which brings me to
2 - You can't photograph everybody, nor should you. Some people don't want to be photographed, and others you will not want to photograph. To make a portrait of an unwilling subject for the sake of "art" (or money) will prove difficult to justify. As for the person you don't like: taking a photo you don't want might be a reality of business, but in my experience it leads to crummy photography.
Now, as far as posing goes... I've always had a problem with this myself. For my documentary photos it's simple: nothing is posed. For my "portraiture" work, I tell them the most important thing is for them to be comfortable. But I think that Nicole, Cheryl Jacobs, and others, would have better advice than mine on this subject.
In the last couple of weeks I started painting with light, and tried a few portraits. When painting with light, you simply need to pose; no decisive moments stand still for 85 seconds... My solution has been to get the subjects to find a confortable position, and go from there. Last night, my brother, his wife, and her brother wanted me to photograph them. After I told them to be confortable, my brother in law said he'd be more confortable being silly. Great! So silly it was, and a silly picture we got; and it was the best picture of the day.
I've attached two photos to this post. Both are digital photos, but I hope they're ok since they're just illustrating a point. Both are portraits painted with light, and my main concern in both shots, as far as posing went, as to get them as confortable as possible.
Anyway, I hope this post makes some sense. I feel like I've been writing in circles...
André