The design of your retaining wall will determine how you mark the area. To mark a free-form design, use a rope or hose to delineate the shape. Then use a shovel to mark the outline. For straight lines, mark the entire area of the bed with stakes, rope and marking paint. Mark the curved corners by attaching a rope to a stake that is equidistant from the edge, creating a compass, and spraying the curves with marking paint. To determine how many blocks you will need per row, divide the total length of the wall by the length of the block. To see how many rows you will need, divide the ideal height of the wall by the height of the block, so that the first row is half buried. See Planning a block containment wall for more information on estimating project materials.
Before buying materials or starting work, check the local building codes and regulations of the homeowners association to see if there are restrictions or requirements that you must meet. A permit may be mandatory in some areas. Watch the following video which shows how it is done.