Survive wearing the exact same outfit as someone else at a party.

Change it up as much as possible. If her hair's down, quickly go into the bathroom and puts yours up. Wearing a skirt? Roll up the waistband to elongate your legs. Double-dress slips-up aren't the end of the world; if both of you notice, point it out, and have a laugh! At least you can say you both have the same taste.