Go Greek
Depending on the age of the party, host a toga party with chaperons or hosts dressed as Greek gods. Decorate the house with paper cutouts designed as columns. Gold, burgundy and white are key colors of this theme. For your snacks serve grapes, feta cheese and Caesar salads. Play games that emphasize the powers of the gods, including an obstacle course to reenact the original Olympics, a Titan tug-of-war and Clash of the Titans -- with water balloons.
Witches and Wizards
A witches and wizards party will involve your guests getting dressed up as well. For a visual aid, take inspiration from Harry Potter. Hire a magician to perform at your party and purchase magic trick sets for your guests to learn. J.R.R. Tolkien was discontented with the mythology of his home country, the United Kingdom, and created his own in the Lord of the Rings trilogy. Decorate or dress up as any number of mythological creatures from his books. Set up a buffet where your guests can concoct their own meal, like a fondue, pizza bar or taco bar. Dangle stars from the ceilings. Cover Styrofoam balls with glitter to recreate a crystal ball. For your cake, use trick candles.
Fairies
Fairies are a favorite of little girls, and sometimes grownup girls too. For children, create or purchase a set of wings for each guest. To make a simple set of wings yourself, use a wire coat hanger. Form it into the shape of wings and cover it with gauze, tulle or even cellophane. Attach elastic bands for the arms. Another option is to decorate cardboard wings as an activity once the party has begun. Have a scavenger hunt and look for particular herbs or flowers. Hang tinsel around the house and decorate with wildflowers.
Dragons and Other Mythological Beasts
The most infamous mythological beast by far is the dragon. "How to Train Your Dragon" is a great theme for younger children. Decorate your home to look like a castle. Cut out dragon footprints and lay them on the sidewalk leading to the front door. Use plastic Easter eggs to play a dragon egg hunt. Play pin the tail on the dragon. Serve dragon wings (Buffalo or barbecue wings) and dragon-scale pizza (pizza with overlapping pepperonis.) Other beasts that can serve as inspiration are unicorns, Pegasus, goblins, griffins and mermaids. Each culture has its own mythology, so decorate according to the nation's traditions.