1. Get latex gloves WITHOUT POWDER. Rinse them well. Fill them with liquid that will contrast color with your punch, twist-tie them or rubber-band them closed, and freeze them solid. Peel the hand-shaped cubes out of the gloves.
2. Make a ton of punch, any kind. Make sure it's really cold.
3. Add "hands" to large punchbowl full of punch. Mmm, grossss.