Matt, some years ago, before had more than a chop saw and a router, I built a mirror for one of our bathrooms. It's all red oak. The frame on the sides and top is a piece of molding typically sold to go around interior doors--usually with those rosettes at the top corners and maybe 3 1/2 or 4 inches wide. The bottom part of the frame consists of a piece of 1x4 oak laying horizontally and below that a bit of a smaller crown molding. It sort of looks like a window frame with a deep sill (stool) I inverted the crown molding so it would be at a steeper angle and cut very short returns.
It doesn't give you a storage cabinet but it was a quick, weekend project. If you're interested I could either take a photo of it or do a SketchUp drawing.
Dave
Inspecting mirrors is a job I could easily see myself doing.