Measure out the area that you want construct your patio using the tape measure. At the corners of the patio boundaries, pound the garden stakes into the ground. Mark the boundaries by stringing the cotton string between the garden stakes.
Cut the sod around the boundaries by inserting the spade into the ground all around the patio boundaries. Remove the sod to a depth of 6 to 8 inches using your shovel. Ensure that the ground beneath the patio is perfectly flat by laying the plywood sheet on the ground and, using the carpenter's level, measuring the surface for flatness. If the ground is not flat, you may remove more dirt or redistribute it using the rake.
Cover the ground with weed barrier. Over this, spread the sand to a depth of 3 inches to form your patio base. Rake the sand until the surface is flat and even. If your patio is next to your house, rake the sand so that it slopes gradually away from the house foundation.
Install your edging around the perimeter of the patio. Plastic edging is typically pounded into the ground using 12-inch galvanized nails.
Lay your concrete blocks on the patio base, taking care to match up all seams and joints. If the blocks do not perfectly fit your patio base, you may cut them to fit using a masonry saw. Fill any cracks and crannies with play sand, and sweep the patio using a broom.