a hinged full length mirror from IKEA (Stave mirror - that is x hides jewelry storage -- brilliant idea from The Girl on the Go! I would use a thin sheet of plywood cut to fit behind the mirror so I don't put so many holes in the wall.
In the bathroom: Trones boxes fit into tight corners to provide a little extra storage. These little guys can go pretty much anywhere. How To Use IKEA Trones Storage Boxes in Every Room of the House — From the Archives: Greatest Hits