Cut a wooden board to the dimensions of 6 feet horizontally by 3.5 feet vertically. This board will serve as the backboard. This is the standard size of a basketball hoop backboard, although it can be reduced, or even rounded off at the top corners to fit any size restrictions.
Take a piece of wood at least 20 inches long and wide, and 3/4 inches thick. Using a ruler and compass, select a center point on the piece of wood and draw a circle 18 inches in diameter. Using the same center point, draw a second circle that is 18.75 inches in diameter. These two circles provide the outline for the rim of the basketball hoop. Cut along the two lines using a jigsaw.
Use a power sander, or sand paper if you prefer, and round the edges of the rim to create a cylindrical shape approximately 5/8" in diameter. Do not sand too much off the inside of the rim, as the hole inside the rim should be 18 inches in diameter at all points. Once complete, screw the rim onto the 6"x6" block of wood at the top of the square so the top of the rim and the top of the block are level. Once this is complete, you can make a diagonal cut in the block to eliminate the protruding corner if you wish. This is not required, but may keep the ball from taking odd bounces after passing through the net.
Attach the rim and block to the backboard. The rim should be positioned in the horizontal center of the backboard, with the 6"x6" block aligned to the bottom edge of the backboard. This setup allows for the required 6 inches of separation between the edge of the rim and the backboard. Using a ruler, draw a 2-inch-thick square centered directly above and touching the 6-inch block. This square should be 24 inches horizontally and 18 inches vertically. Paint the square outline in a solid color. Traditionally, white, orange, red or black is used.
Measure exactly 10 feet from the ground, where you plan to mount your basketball hoop. Mounting on a garage or barn provides stability, but mounting on a pole that is cemented into the ground provides flexible and will not damage your house. Decide where to place the basketball hoop, then secure mounting brackets to the back of the basketball hoop using nuts, bolts and washers. The location of these fasteners will depend on where you decide to mount your hoop. Attach a basketball net using tiny hooks screwed into the bottom of the basketball rim. Position the hooks around the bottom of the basketball rim to match the basketball net accordingly.