Built-In Drawers between wall studs. We did this with our bathroom vanity. The doors to the vanity consist of mirrors mounted on plywood. It's a great space-saver, and the mirrors make the small space seem much bigger.
Excellent idea for the fireplace mantel... especially at Christmas time! ALWAYS ! I put outlets on wall just above mantle so no cords show & hid it year round w decor .... Also every high self has outlets for small lamp if there's room between ceiling & shelf ... There should be, but mainly for twinkle lights... It gives a beautiful ambiance to each room !