Dig up and upturn the soil as much as possible, to a depth of at least 6 inches, with a tough tilling tool. Tool options include a sharp shovel; a handheld, pronged tiller; or a gas-engine push tiller. Leave the soil upturned for several days to allow it to aerate.
Sprinkle the turned soil generously with compost and coarse builder's sand. Add approximately 2 to 3 inches of compost and 2 to 3 inches of sand. Till the soil again to blend in the compost and sand.
Introduce native earthworms to the soil. Earthworms will excrete healthy humus into the soil. Find earthworms from a local worm farmer, garden store or bait supplier. For further information regarding local resources for worm acquisition, contact your local cooperative extension office.
Till the soil one more time in early winter, before the ground freezes, to further break up and blend the now-softening soil. Rake the soil and level the ground slightly.
Add another thin layer of compost in early spring. Re-till and rake the soil to finish refining the now-softened soil.