The most appropriate costumes for harvest parties are biblical costumes. Even for regular Halloween parties, a biblical costume is a great way to witness. The three wise men make a good choice for a group of three friends. Joseph and Mary on a journey make a good costume for a couple. Joseph's multi-colored coat makes a very easily identifiable costume. It is best if you don't have to explain yourself all night. Try to think in your mind, which biblical character you can visualize. Then try to picture what aspect of the clothing comes to your mind. Another way to search is to use a word look-up tool, based on descriptions of items you have on hand. Sandals are a must for Biblical costume.