MY 18th Birthday!!!

Hey!!! my super sweet 18 is in about 5 months and i usually had birthday parties where relatives or friends just come over for cake and presents. My sweet 16 was a little more special b/c my mom invited her whole side of the family over (14 people) and i received a "16" figurine from precious moments from my other grandmother which i really treasure. Does anybody have any ideas that will make a sweet 18 even more special? it needs to be pretty inexpensive and preferably a theme. Any ideas for an outgoing and fun-loving girl that`s a girly girl teen?