Sand the ends of all PVC pieces with 80-grit sandpaper. This will roughen up the surface, allowing the glue to hold more firmly.
Apply PVC glue into the lower three flanges of two, 1-inch 4-way PVC joints. Insert a 6-inch pipe into the outer flanges and a 3-foot pipe in the central one. This will create a long "H" shape with the fourth flange on each joint facing upward.
Wipe off any glue that oozes out of the connections with a paper towel.
Glue the 5-foot pipes into the upright flanges on the "H" shape.
Glue 1-inch PVC end caps onto each of the four feet.
Allow the glue to dry for 24 hours, then fill the section that you have built so far with sand. This will make it more bottom-heavy, helping to stabilize it.
Glue two 3-way T-joints onto the ends of the last 3-foot pipe, then glue the final 6-inch pipes into the flanges opposite of the longer pipe. The third flange on each joint should point down.
Glue the downward flanges onto the tops of the 5-foot pipes, completing the rack.
Glue a 1-inch PVC end cap onto each of the side pipes.
Allow the glue to dry for 24 hours before hanging clothes on the rack.