No tools necessary....concrete blocks spread evenly with osb board over them. You can cut the osb board yourself, or most if not all home improvement stores will cut the size you need for a fee.
Step 1: Need a Heavy Duty Bed Frame
I needed a bed that could handle about 600 pounds of weight and wouldn't move. It should be noted that my home is built on a slab, so concrete blocks won't harm the floors. We had been having the box spring and mattress on the floor for several years, but this was beginning to be too hard on the knees when getting up.
Step 2: Measure for Size of Osb or Plywood You Need.
I found that about 80% works well for both length and width. You will definitely want your mattress and/or box spring to hang over a few inches past the osb or plywood so your skin doesn't come into contact with it getting in or out of your bed.
Step 3: Finishing Touches
I have my original headboard between the bed and the wall....looks fine. I will have my wife pick out a bed skirt to hide the "frame". I have about $12 total in the frame. Concrete blocks are about 90 cents a piece. Osb is about $10 per 4x8 sheet. I like to use the osb instead of plywood because it is A; cheaper, and B; keeps the mattress and or box spring from sliding around.