Harsh Lighting
If you have moved beyond the on-camera flash and you have started to experiment with bounced or filtered light from an off camera flash or light, it is not enough to simply move the light away from the camera. While it is an improvement and the photo will have more dimensionality than the on-camera flash, it is still rather stark.
While there are many factors at work, if you are just starting out, greater diffusion will tend to warm up your portrait and help you create a more flattering portrait.
As a note, harsh light can include poorly managed sunlight.
