What's your lucky charm?

Do you have a specific item(s) that you hold, use, wear, etc… during a specific event or time in your life as a lucky charm (figurine, shirt, rabbit tail)?

If so, what is it and for what event (final exam, sporting event, just life in general)?

Why do you use it as a lucky charm? For how long has it been your lucky charm? Do you believe it actually works or are you just hopeful that it works? How often has it been good for you?

What are your thoughts about lucky charms?
Not the cereal… unless that is your lucky charm!