You're using the bathroom mirror whilst applying makeup or shaving. But no matter what time of the day you do this, you never seem to have quite enough light so see what you're doing.
Consider...
Installing bright lighting around the entire perimeter of the bathroom mirror. If you don't want to end up with a backstage mirror look (and hey, some people like this style), further consider recessing the bathroom mirror into the wall and then placing the lighting within the recessed sides.
Additionally, the bottom of the recess then becomes a shallow shelf upon which you can place items that would typically clutter up the bathroom bench - liquid soap dispensers, hand creams, small pot plants, etc.