Step 1 : Construct a raised bed of any size, using one of several methods. Kept to no more than 4 feet deep, the bed will be easier to reach or step across. Use lumber, such as 1-foot-deep boards, or landscape timbers; concrete block; or recycled plastic lumber in snap together parts. Buy plastic corner caps that interlock wooden lumber together parts almost instantly to make a bed without nails or screws. Or, use nails or deck screws to secure the joints.
Step 2 : Secure the raised bed frame by burying the bottom of it 2 inches into the ground. Drive a stake into the soil at each outside corner of the bed; nail or screw the stakes in place. Add any commercial topsoil (avoid fill dirt that could contain weed seeds) and any organic materials, such as compost, chopped leaves, rotted manure, and grass clippings. No need to dig or till raised beds every year -- just add layers of organic matter.