What sets the environmental portrait apart from candid portraits is that you post your subject (it’s a fine line and you might end up doing a bit of both in any given shoot). Don’t be afraid to direct your subject to sit, stand or act in a certain way that fits with the environment that you’re shooting in. Some of the poses might seem slightly unnatural and dramatic but it’s often these more purposely posed shots that are more dramatic and give a sense of style to your shot.
The expression on the face of your subject is also very important in environmental photography and you should consider how it fits with the overall scene. For example if you’re shooting in a formal environment it may not be appropriate to have your subject with a big cheesy smile and you might like a more somber or serious look. Again – mix it up to see what does and doesn’t work.