Also.... set design. There's a lot of clutter in the top right corner, and that scratched wooden monitor shelf ain't too hot. Consider constructing sets for your shots, or make sure your desk space is immaculate.

As for your shot, you appear to be using one light source, and it's very heavy to the left hand side, leaving the right hand side of the shot dark. Consider two light sources... on left, one right, and have one as a main light around 50% brighter than the other. Again... there are no hard and fast rules, and some shots look great with one light... or front lit... or backlit. Practice... experiment, and try different lighting set ups.