Determine the perimeter of your lawn by pounding in wooden stakes at corners with a rubber mallet and stringing twine between the stakes. In areas where you want a bend, use several garden hoses connected together to form a pleasing curve.
Spray a line to mark the perimeter you have laid out. Convert the measurement into inches. Use landscaper's spray paint. Remove the stakes, twine and hoses.
Calculate how many concrete blocks you need by dividing the length of each of the blocks you have chosen into the total measurement of the perimeter. If you have created a curve, subtract the length of the curve from your total measurement. Find the number of straight concrete blocks by dividing the length of the block into the measurement of your perimeter minus the length of the curve. Calculate the number of curved concrete blocks you need by dividing the number of inches in the curve by the length of one curved block.
Measure the height of your concrete block. Determine how much of the top of the block you want to extend above the grade of the lawn. Subtract that measurement from the height of the block. Add 2 inches to the remaining number. This is the depth of the trench you will need to dig. The width of the trench is the width of your concrete block plus 1 inch.
Dig a trench along the line that indicated the perimeter of your lawn. Use a shovel with a pointed end to make the first cuts. Then even out the trench to make it the correct depth and make the side of the trench closest to the lawn absolutely vertical. Tamp the bottom and vertical side of the trench with a 2 x 4 piece of lumber to make the trench consistently deep and wide and to make a stable bed for the concrete blocks.
Fill the trench to 2 inches deep with coarse sand. Tamp down the sand and then lightly water the sand so it will pack down. Tamp again.
Lay the concrete blocks end to end in the trench. Use the 2 x 4 to push the blocks hard up against the inside edge of the trench and to check that the blocks are an even height above the grade of the lawn. Continue until all of the block are laid. Fill in the front side of the border with coarse sand, topped with an inch of crushed gravel.