Free your hand of any objects. You can't give the peace sign effectively if you have anything at all in your hand.
Raise your hand, palm facing forward, with all fingers and thumb extended.
Lower your pinkie finger, ring finger and thumb, placing your thumb over the two lowered fingers.
Widen your middle finger and index finger so that they form a "V."
Keep your hand still so everyone can see the peace sign. Once you know everyone understands your intentions, lower your hand to a natural position to end the peace sign.