Light is paramount to your images. Understanding light will improve your craft. Today we’ll talk a little about the direction of the light. Straight on frontal light often results in an evenly lit boring subject. You are taking a 3 dimensional subject and rendering it 2 dimensional in a picture. The last thing you want to do is make the subject more 2 dimensional by erasing any shadows that give depth and modeling to the subject.
On camera flash is one source of frontal light. This straight on light washes the subject out and erases any depth or dimension to the subject. Also using the old technique of placing the sun behind you and having your subjects stare into the sun. Not only is there no depth to the subject, but they are cranky and squinting.
So work on finding ways to change the direction of the light. When outdoors find an overhang and face the subject so the light comes in at an angle, usually around 30-60 degrees to give depth to the face.
Get a flash for your camera with a rotating head. This way you can bounce the light off of a wall or ceiling. Use window light and adjust the subject so it is lighting the side of their face.
Observe how the light strikes your subject. Look at portraits made by professionals and see how the light is striking the subject. All of this will teach you to see better and subsequently make better images.