Photos of people we meet while traveling often bring home very intimate memories, nothing compares to a powerful portrait from a far-off place to remind and inspire.
I am suggesting approaches that would, most likely, be considered photo-journalistic travel photography, still others think of these shots as environmental portraits. There is much debate on respecting people and always asking to take their photograph, respect is always in order, but also consider what photojournalists do. Photojournalists are witnesses to an event, recording images for the benefit of history, this does not include asking permission.

The best way to find those faces that define character, deep wrinkles, heavy set eyes, or my favorite, a great defining nose (think Incas) can be simply to wander, find the local fish market, stop at the passing farm, people working or enjoying their day at the park can make for great portraits. In these situations, working candidly (that is, unobtrusively) is often your only alternative, as subjects come and go quickly. A great telephoto lens like an 80mm to 200mm zoom, will enable you to remain at an inconspicuous distance. Although there is a fine line between working politely from a distance and appearing sneaky. If you are perceived as the latter, you will certainly draw more suspicion than cooperation. If you’re spotted by your subject, seize the opportunity to start a conversation in which you can ask them to pose. It may not be the photo you were hoping for, but it could turn out spectacular, especially if they are curious about you. If you are a digital photographer, do not forget to show them the picture you took.
That being said, when you do get candid pictures, always try and approach the subject to have a more relational interaction, people are not just part of the scenery, don’t make the mistake of treating them as such and this could lead to a situation where you get even better candid photos.
If you are in the same place for awhile, consider sitting in one place for a bit with your camera at hand, in sight of everyone. Slowly, people may approach you, when they do, point at the camera and smile, if they smile back, try pulling your camera up for a shot, you will know if the person is comfortable with this or not, after awhile people will forget you are there, going about their own business while you are taking as many photos as you like. This technique can lead to stunning portraits of local people. Visiting the same place more than once in this way, can make people very comfortable by getting used to seeing you with your camera, leading to unexpected friendships or even free bread from a Tibetan monk.
Posing someone for a portrait isn’t always the goal, candid or unposed pictures can remind that you witnessed something special, a new culture, new experience or event. Frame the scene tightly to take in just the head and shoulders, especially good with an 80mm-200mm but can also work well with smaller lenses (24-70) and try to keep direct eye contact with your subject. Don’t automatically encourage people to smile: Always allow them to be shy or pensive or curious, let their personality show, it will show in the photo.

Background Blur, Tibetan Barley Farmer
Portraits look best when the background is either simple or out of focus; one technique is to use a large aperture and selective focus to cast the background into a soft blur, another feature you may try is Aperture Priority to blur a background. Even lighting is most flattering, try to pose your subject in the shade, this may include your own shadow. Bright midday light from overhead is the worst; it will create strong shadows under the eyes, use fill flash in this situation to overcome the shadowed face details if you want bright clear photo, if not, let the shadows play on the face, it may create a very dramatic portrait.
Finally, remember that there are places in the world where taking someone’s picture is taboo, some believing it steals the soul. Do the research, know where you are going and the likely habits and beliefs of the people you will find there.