Step 1: Supplies
If you want to make larger pom poms, you'll need a bigger fork, like a salad serving fork.
The pom poms I'm making in this tutorial are about 1 inch in diameter (marked "small fork" in the image below). I used a simple dinner fork.
Step 2: Wrap Your Fork
For small pom poms, wrap the yarn around the fork about twenty times. Keep your wraps tight. Also, be sure to center your wraps in the middle of the fork, leaving space at the bottom and top of the fork.
If you want a fuller pom pom, or you're creating a larger pom pom, wrap the yarn around more (the large pom poms pictured previously were wrapped around a larger spoon 50 times).
Don't be afraid to experiment with the size and amount of wraps. You can also extend the length the yarn covers the fork. Just be consistent. If you want all of your pom poms to come out the same size, use the same fork and wrap it around the same number of times for each one.