Body Language

It's been told that 94% of body language is non-verbal, so of course it's a very important part of taking a portrait.
The slightest difference in your body language can set a specific mood or tell a story.
Props and composition are other key factors that can have an effect.

Arms:
The position of arms is an obvious sign of detecting the mood of a person. For example:If the subject is seated and places their head in their hands comfortably, this can imply boredom.
If the subject places their arms across their chest, this suggests they are feeling uncomfortable and possibly defensive. 

Head:
Overly tilted heads can be a potential sign of sympathy. If a person smiles while tilting their head this can imply they are being playful or even flirty. 
Lowered heads indicate a reason to hide something.
Cocked heads mean that they are confused or challenging you, this can then depend on eye, eyebrow and mouth gestures. 

Eyes
If someone looks to the sides a lot this can be a sign of being nervous, distracted or lying. If someone looks down at the floor a lot, they are probably shy or timid. Feeling negative, or thinking unpleasantly can often lead to staring at the floor.  
Dilated pupils mean that the person is interested.
If their eyes seem focused far away, that usually indicates that a person is in deep thought or not listening.

Here are some pictures I took to show different ways of showing emotion through body language. 

Exposures: f2.8
ISO: 200 
Shutter Speed: 1/125


I loved this shoot, it was fun and I think the use of camera angle helped capture the emotions, as well as the use of arms and eyes.