Find an area in full sunlight that is flat and large enough for the size of box you want to build.
Remove all sod and weeds from the building surface. Mark the dimensions of the strawberry box on the ground by placing a stake in each corner. A raised strawberry box is generally 4 feet by 8 feet, or 4 feet by 4 feet.
Remove the top 4 inches of topsoil and level the building surface. Place 2 inches of pea gravel as the first layer to assist with water drainage.
Cut a piece of weed-prevention cloth to the dimensions of the box, and fit it over top of the pea-gravel layer.
Cut landscape timbers to fit the dimensions of the strawberry box. Place the first layer of timbers on top of the weed-prevention cloth and secure them at the corners with long nails. Place two additional layers of timbers on top of the first layer and secure them with long nails at the corners and along the sides.
Support the box by pounding one or two stakes on each side so they are flush to the box and about 6 inches into the ground.
Fill the box with a good-quality planting soil made from 3 parts topsoil and 1 part compost. Large quantities for several boxes are available from landscaping companies at a lower cost than bagged soil.