Drill two 1/8-inch pilot holes 3/4 inches apart in the center of a 2-by-6 board 6 inches in length. Drill two matching pilot holes on one side of a 2-by-2-by-4 block of wood. Drill a pilot hole, centered, into the other side of the 2 by 2. Drill a pilot hole through the wood ball that will serve as the form for your clown's nose.
Turn two 3-inch wood screws through the 2 by 6 into the 2 by 2. Turn one 3-inch wood screw through the wood ball and into the 2 by 2.
Choose a piece of leather that is thick but pliable. You need about one square foot of leather.
Bring a pan of water to about 180 degrees. Immerse the leather into the water for about a minute. The leather will darken and go limp. Lift the leather out of the water using tongs.
Spread the leather over the wood ball and stretch the leather down and around the sides of the ball. When the leather forms to about three-quarters of the ball, wrap the leather at that point with heavy duty rubber bands and allow the leather to dry completely. This should require at least 24 hours.
Remove the rubber bands and work the nose off the ball. Examine the nose for the best way to fit the nose to your real nose. Slowly trim back the excess leather using leather shears until you can actually turn the leather on your nose. Look in a mirror and begin to trim the leather carefully to shape it perfectly to your nose. Mark your nose at the top so you can identify the top each time while you work on it.
Trim until the ball of the nose looks good and fits your nose comfortably. Use an awl to punch two tiny holes in each side (for the silk string). Punch nostril holes exactly under your actual nostrils and wide enough to allow you to breathe easily.
Paint or stain your nose the color you prefer. Thread silk from inside the nose, through the awl holes and knot the ends so that the knots can't be seen.