A surprise birthday party at a sophisticated restaurant is an idea for an 18th birthday. It signifies that the guest of honor is an adult now and should have a celebration that is especially refined.
A scavenger hunt may also make an 18th birthday party fun and memorable. Party guests receive instructions to find quirky items around the city or take photos at city landmarks before reporting back to the guest of honor's home for dinner and dessert. The pictures from the scavenger hunt can be given as party favors.
An outdoor party may also be suitable for an 18th birthday. For instance, a party at the beach or by the pool works well for a guest of honor who loves swimming and warm weather. Renting a large projector to play a movie or display pictures of the birthday boy or girl can make the party even more interesting. Food for the party can be prepared on the grill, or party-goers can eat some of the guest of honor's favorite snacks from childhood as a nod to the fact that the 18-year-old is now officially an adult.
A themed birthday celebration featuring characters from the 18-year-old's favorite movie, such as "Hunger Games" or "Harry Potter," may also be enjoyable.