1. Increase your ISO
To prevent motion blur appearing, while your model moves around, you'll need to use a fast shutter speed. This will also help to sharp your shots and avoid camera-shake. Specially if you are shooting handheld.
While in Aperture Priority mode and maintaining a wide aperture, to increase your shutter speed, you just need to increase your ISO.
2. Lens choice
For portraits a wide-angle lens is a must. Because shooting from a low angle will make your model taller than they actually are. This is a great technique for fooling the eye and changing the perspective. Always pay attention to what's going on in the background.
3. Make your model feel comfortable
You need to make your model feel comfortable, then otherwise the shots aren't going to work. Take time to chat with your subject before the shoot- talk over your ideas, about life etc.
When the shoot begins, offer them direction - be comuncative. Tell them what you want and how you want them to pose.
4. Focusing your camera
If your are using wide apertures (especially f/2.8 or even faster), your depth of field decreases, so it's very important that you're focusing, otherwise you could end up with out-of-focus pictures; try to focus on their eyes.
Slect a single autofocus (AF) point, for help.
5. Be creative
Don't be lazy with your compositions. Change it up and try different things.
Zoom in instead to fill the frame for a more inspired photo composition. Positioning your model to one side of the frame, then change it up. Your goal should be, to have a couple of good shots and specially different ones.
No go grab your camera, ask a friend or a model to pose for you, and take some