The steps involved are as follows:

Obtain two empty soda cans (or other similar cans). Tin cans work better than aluminum. Using a can opener, completely remove the opened end. Make sure there are no sharp edges left. Use pliers to clean up any rough spots. Wash the can thoroughly. Using a sharp awl or nail, poke a very small hole in the center of the bottom of each can. Poke two holes, opposite each other, in the side of one can, very near the open end. Push the "E" string out through the hole in the bottom of one can and in through the hole in the other can. Hold the string in a pair of pliers and twist a small loop into the free end of the string. Insert a spare string ball-end and twist the loop tight. This will keep the string from pulling through the bottom. Tie a piece of twine to the can with the two holes, making a loop large enough to allow your upper arm to pass through.

Hold as shown in the pictures, with the string around your right upper arm, the far can in your left hand, and a thin flat pick in your right hand. By stretching and releasing the string, the tone gets higher and lower. The sound is similar to a mouth bow or a Tremoloa or a musical saw. With practice, whole tunes can be played. Coffee cans make a good bass Tension Banjo. This is 100% recycled, limited only by your imagination.