Determine the length, width, and depth of the area where you want to pour the cement. Multiply these measurements together to figure the total area. Visit a lumber store or home improvement store and buy correctly-sized pieces of coated lumber to construct the frame that you need.
Remove any garbage, debris, plants, grass, and other items from the area where you want to pour the cement. Make sure the surface is solid, even, flat soil. Assemble the supplies to build your frame in this area. You cannot move it from another location later, so build it on-site.
Use a tape measure to measure 1 foot from each end of both of the longer boards and mark these measurements with a pencil. Turn one of the shorter boards up on its side so that the shorter edge is positioned vertically. Place this shorter edge against one of the pencil marks on one of your longer boards. Clamp the 2 boards together. Use a hammer to nail the boards together, making a straight row of 3 to 4 carpentry nails through the flat side of the long board into the edge of the shorter board. Attach the second short board to this first longer board in the same way. Place the second long board so that the pencil marks on it match up to the unattached edges of the short boards. Clamp this long board to the short boards to hold it steady and then nail it into place as you did the first.
Place a 2 x 2-inch wooden stop pin every 2 feet around the outside perimeter of the frame. Use the hammer to sink each pin into the ground approximately halfway. With a hacksaw, cut off the top of each pin to make it even with the top of the frame.
Use a shovel to make a trench along each inside edge of the frame that is 4 inches deep and approximately as wide as the spade of your shovel.
Use a garden hose to wet the soil within the frame to make it soft. With a long-handled, hand-held tamp, tamp the soil down to make it level and tight. Pour your cement as directed.