Try This: Scrap-Lumber Vanity Shelf

Turn scrap heap into bathroom chic

Drill the hole for the vase and jigsaw the notch for the mirror. Set the top and bottom of the shelf on edge, lining them up carefully about 4 inches apart. Place the two end dividers 6 inches from the ends as shown. Predrill four holes for each divider, then glue and nail them in place.