This DIY Modern Bed is made from a sheet of ¾” plywood, and 10 ikea shelf brackets. The materials cost less than $100 and only 3 power tools are needed to build it. Full instructions can be found at HomeMade-Modern.com
How to make your own fitted sheets. Tutorial is for a crib-sized sheets but includes directions at the end for how to do adult-sized beds too. Good use for those flat sheets that you otherwise never use!