A photographic portrait can say a lot about a person. A Landscape photograph can say a lot about a place. Put them together and you can tell a story about the person and their place in the world. The challenges of environmental portraits are that they require good photographic technique for landscape as well as portraiture. Your subject must appear comfortable in their surroundings, visually integrate with the elements of the landscape, and the landscape aspects of the image must also be compelling. This is no small feat. Timing is everything; light, subject posture, and expression have to merge to create an interesting photograph.

Light;
Environmental portraits can be made in any environment indoors or out. Both situations require a good command of your photographic technique and knowledge of "fill flash." Because all uses of your flash should be considered "fill flash," anytime you use flash you should be thinking about how to integrate it with the ambient light that exists in the scene.  I don't have the space in this article to adequately cover use of flash I will put that off for another article at a later date.  Just about any ambient light can be used for portraiture. Mid-day sun is harsh, if you have no choice but to shoot under these conditions consider back lighting your subject and fill in with your flash in TTL mode.

Place;
Your depiction of the environment in an Environmental Portrait is a critical component of a compelling image. Equal regard must be placed on the surroundings as well as the person. Emphasize the intriguing aspects of the landscape. For instance if the sky is dramatic make sure you include plenty of it in the photograph.  Scout locations before your photo shoot. You may want to go so far as to photograph the landscape first and then look at the resulting image and consider where you would place a person within the image.

Placement;
Where you ask your subject to pose. Your subject should feel comfortable and safe in the environment where you are photographing them. Allow them to get settled in. Tell them about the image you envision, and ask if they have any ideas to add to the image making session. Good portraiture is collaboration between the photographer and subject.

Timing;
Have your subject move or go about their business as usual. Spend the first few minutes observing them. If you are having them walk through a landscape just watch them the first time through. You should be watching them to see at what moment all the elements of the image converge for greatest impact. You can then ask your subject to repeat the process for purposes of the actual photograph.

Experiment, take chances, and most important have fun!