Place the male end of the hose adapter into the female end of a threaded PVC pipe. Turn the adapter clockwise until tight. This is the connecting point between the garden hose and the sprinkler.
Place the male end of a 90-degree fitting into the other end of the threaded PVC pipe, and turn the fitting clockwise until tight.
Place another section of PVC pipe onto the other male end of the 90-degree adapter, and turn the pipe clockwise until tight. You now have a basic L-shaped sprinkler. You can continue to add adapters and sections of pipe in any desired shape or pattern before moving onto the next step.
Place a PVC plug into the end of the sprinkler, and turn it clockwise until tight.
Press a drill with a 3/16-inch drill bit into the top of the PVC pipe every 2 inches along the pipe until you reach the end of the sprinkler. These holes will be where the water will jet out, so only drill holes where you want water to escape. Vary the angle of the holes to create interesting spray patterns.
Screw the end of a garden hose into the garden hose adapter at the beginning of the PVC sprinkler, and turn on the water at the tap to begin spraying water from the new sprinkler.