Roll out the copper refrigeration coil and then measure and mark four equal pieces. If using a 20-foot roll, each piece should be five feet long. Mark the halfway point on each leg, and bend on that line until you achieve a hairpin shape. Be careful not to bend too sharply or the copper may collapse. When the pieces are the right shape, trim them down to desired leg height, plus an extra two inches for bending the ends flat to attach to the tabletop. For a nightstand, 20 inches is a good leg height to start with.
If you plan on spray painting the hairpin legs, now would be a good time to do so to allow time for the paint to begin drying.
To build the box top of the nightstand, cut 2' x 4' sheet of plywood cut into two 6" x 18" pieces and two 18" x 24" pieces. If you don't have a power saw, have the hardware store cut the wood for you. Use strong wood glue to attach the pieces of plywood to form a box shape. Reinforce with finish nails for long-lasting hold. Use sandpaper on the corners and edges of the box until smooth.
If you want to stain the wood, do so now to allow time for drying. Apply one coat at a time with a small cloth until the desired color is reached.
Drill two holes in each end of all four legs. Measure and mark where you want the legs to attach to the base of the wood making sure they are equidistant. Use the drill to screw each leg into the wood. Flip the table over and bend each leg to adjust table height and to ensure the top is level.