See what highlighting and contour can do? Why can't every girl know this? (tip: when you do highlight and contour you dont need that much eye, lip, blush makeup as she is; that is why you do it so you have a more natural look)
Jessica's long layers, as well as her side-swept bangs, make her hair appear fuller. Make sure to focus the layers in the front. Too many layers around the entire head can have the opposite effect and make the hair look too thin.