Being beautiful is not the same as being photogenic. You may be both (lucky sods!) But they are not mutually exclusive.
However, you can become more photogenic with a few tricks and a little practice.
Here are my favorite tips to looking better in any photo:
DO add tension in your eyes (“squinching” or “smizing”)
DO push your jaw and forehead in front of your neck (“the turtle”)
DON’T take a photo if you are backlit (the light source is coming from behind like standing in front of a window). The goal is to have light hitting your on your face (flash photography and facing a window or light source).
Here are two great videos by photographer Peter Hurley: