Harsh sunlight will ruin a image. It will cause harsh shadows to the face, make the nose and chin look bigger and make the eyes look like big black holes. We need softer light, so if you are struggling with shadows move your subject into the shade.
Depth of Field
Most portraits we want to use a shallow depth of field to blur out backgrounds and make the subject stand out more in the image. A nice close crop combined with a wide open aperture (low f number) will give you a lovely blurred background and a professional feel to the image.
When we are dealing with a shallow depth of field we need to make sure that we are focusing on the eye. If any of you use a 50mm f1.8 lens you will have to be very careful that you don't blur out the wrong part of the image. Focus on the tip of the nose and the eyes might not be as sharp as you would have hoped.
Remember an awkward pose will ruin the shot. Keep things simple. Make sure that their shoulders are relaxed, their elbows, wrists and fingers are all bent.
When we are trying to create a simple yet effective portrait, we need to make sure our backgrounds are nice and neutral. you don't want anything to colourful or cluttered as they will become a distraction and draw attention away from the subject.
If you are struggling for light, or the light is very harsh and causing many shadows you may want to add some fill flash to the image. Fill flash will add light on to the subject and fill in all those nasty shadows