A mobile is a delicately balanced assemblage of lightweight objects suspended by strings. The slightest movement of air will set a mobile in motion.
To make a simple mobile, tie or glue various shapes (circles, squares, animal forms, flowers) to a central string. Cut the shapes from construction paper or medium weight cardboard. To add texture and interest, incorporate balsa wood, colored glass, or natural objects such as shells and nuts.
More complex and interesting mobiles can be created by incorporating one or more horizontal arms into the structure. The arms should be rigid, yet lightweight. Slender wooden dowels or 14- to 20-gauge galvanized steel wires make good arms.
Use string or nylon fishing line to hang an object or shape from each end of an arm. Hold the arm between your thumb and forefinger to determine the balance point, knot a string there, and lift the mobile by the string to make sure it hangs level.
Create other arms by the same procedure and add them to the structure. Work from the bottom up, checking the balance of the assemblage whenever a new arm is added. For visual interest, vary the size of the shapes and the lengths of the threads. Display the finished mobile in an open area where it can move freely.