101 Portrait Photography Tips http://improvephotography.com/1305/101-portrait-photography-tips-to-improve-your-photography/
2/3rds Turn Instead of having the person face square to the camera, position them them to a 2/3 turn away from the camera.
Lighting Position the person so that the light goes across them instead of at them. Use natural lighting. If inside, position in front of a window.
Think About Photographing From Behind Shutter speed: 1/160, Aperture: f/8, ISO 200, Camera: Canon 6D, Lens: Canon 24-105mm lens, Lighting: Einstein studio strobe at half power with a beauty dish placed above and in front of her using a boom stand.
Chin Down This helps us avoid what is going on in their nose and mouth, and the open eyes open up.
Diagonal Lines When your person is nervous in front of the camera and goes into performance mode by keeping their hands and arms straight down their side. break that up the vertical and horizontal lines by introducing some diagonal lines into the photo. You can easily do that by having your person put their hand on their hip or in their pocket.
Choose your poses before the shoot. Making a shoot list and possibly printing off some examples can help you to keep the energy of a shoot moving. Sit down and spend some time thinking of creative poses, and when you get out to shoot portrait photography, don’t be afraid to try some new things. http://www.youtube.com/watch?v=qy3RVRFVmUE
If using a film camera, the ISO is your film speed