Purl sells a Pom Pom Maker from Susan Bates that turns out wonderful, fluffy pom poms. However, I have on more than one occasion witnessed customers look at all the little pieces and the instructions and then at me, "Huh?" If you don't have the convenience of a Purl staff member at your side, you may find this tutorial helpful...
The Pom Pom Maker comes with forms for four sizes of pom poms. Each size has a set of four color coordinated pieces. Select a size and disconnect the pieces from each other so that there are four separate U-shaped pieces, 2 with smooth backs and 2 with bumps on the backs.
Taking 1 smooth and 1 bumpy piece, place them back to back, so that the little feet are facing outward. (At this point, the pieces are not connected in any way.)
Holding the pieces together, start wrapping the yarn around the U shape.
Keep wrapping, traveling back and forth until the arch under the U is full.
Repeat this process with the other set of pieces.
Then, interlock the feet, joining the two sides into a donut shape.
Next, carefully cut around perimeter of the circle.
Slide a piece of yarn between the halves of the pom pom, pull tight and tie a knot.
Then gently remove the plastic pieces, trim any defects if necessary and voila!
Try holding two or more yarns together. Or filling one half with one color and the other half with a different color, or different yarn... Or whatever else you can think of. It's hard to make a mistake when it comes to pom poms!