Tell everyone to dress in “summer” attire, as if they were actually on the Island. Shorts, Hawaiian shirts, t-shirts, etc. Since lost is filmed in Hawaii, place a flower lei around their neck as they come in the door.
Serve plates that include foods that were consumed on the Island. Fruits like mangos, bananas, pineapples, coconuts and papayas. No, you don’t have to go as far as roasting a wild boar, but something like ribs or shiskabobs will do. Make tropical fruity drinks like pina coladas.
Play Lost trivia. Come up with some pretty tricky multiple choice questions that have to do with the characters, Island, or events in the series. Having trouble coming up with good questions? There are a ton of “Lost quizzes” and “Lost trivia” websites out there where you can get ideas and questions from.
Play “which Lost character am I?”. Tape a notecard with the name of a character to everyone’s forehead where they themselves won’t be able to see it. Let everyone loose to talk to and interact with each other. Based on clues from the other players they must guess what character they are. To make it more difficult don’t choose easy main characters.
Lost is known for its many mysteries. Discuss and debate some of these mysteries. Share your theories and/or guesses as to what some of them might be. If you want to make it interesting make some friendly bets against each other.