1. Starting with your dominant hand in a "5" handshape (all fingers extended and spread).
2. Bringing the hand to your forehead, palm facing you.
3. Wiggling your fingers quickly back and forth.
Note: The sign can be slightly modified depending on the context. For example, if you are asking someone "How are you?" and they are "fine," the sign can be made with a less vigorous movement.
Let me know if you have any other ASL sign questions!