How to curl naturally-curly hair to get a looser curl??? Urgent help for quinceneara!?

Wash your hair the night before and roll it into two or three high buns (and sleep in those). That will get you in the ballpark, and from there you should use the 1 or 1.5 in. curling iron. Remember to put a heat protectant in the night before right after you wash your hair--it will keep your hair semi-safe from heat damage, in addition to smoothing the frizz. If the curling iron still isn't working, spray a light hairspray on the section your are about to curl before you curl it.