Getting yourself into the right place at the right time is the key to creating a great photograph. Sometimes it is easier said than done. I believe it all comes down to timing and being able to read the situation before it happens but sometimes it can be just up to luck.
Having travelled and professionally photographed throughout a good portion of the world has allowed me to develop some techniques for choosing that perfect moment. A good photographer will be able to see the image that he or she is looking for before picking up the camera and looking through the viewfinder. To be able to compose your image in your mind before hand will allow you more time to get yourself in the right position.
To be able to get natural moments the camera should be the very last thing that comes into play to capture your image. The majority of the time no matter what part of the world you are in a camera will make most people freeze or at least become self aware and at the same time make them aware of you. If you can ease your way into a situation without your camera being noticed then you will have a much greater chance of achieving a great natural image.
Alternatively if the image you are chasing requires you’re subject to look directly at your camera, before approaching your subject have all your settings correct and your composition that you have seen in your mind ready to go. Sometimes you will only get one shot so be prepared to get it right first time. When approaching your subject, wait for a break in their conversation or activity and always have a smile on your face and introduce yourself. You need to portray confidence in what you are doing so your subject feels the same way about you and will be more likely to give you permission to take their image.
Always get your subjects permission. Even if it is a reportage shot show the subject your image after you have taken it to see if they are happy with it. Many times I have seen tourists trying to get images of locals without their permission and more often than not they make a point of looking away or hiding from the camera. It may be a strange new world you are visiting but not the locals. Would you like to be walking down your main street with someone trying to take a picture of you without permission?
Showing respect to the local custom and culture will get you a long way. If you are not sure ask. A good example is when entering a Ger (traditional Mongolian home) it is a great sign of disrespect to walk or even go near the centre of the Ger. Always thank your hosts and eat whatever they offer you.
When travelling in second or third world countries I have always found the locals to be the most generous hosts. I have had prized sheep and chickens killed and cooked on the spot just so they would have something to offer me. To not eat what is sometimes their whole week or month’s food supply would be the worst thing you could possibly do.
It really comes down to common courtesy and politeness. Act as a local and you will be treated as one allowing you to move more freely to capture the images you are after.