Counting down the days until Christmas is even more exciting when each day brings a little piece of your favorite fandom! Creating a DIY geeky Advent calendar is a fun and customizable way to make the holiday season special. Here’s a guide to crafting an Advent calendar filled with surprises for geeks of all ages.   Step 1: Choose Your Theme Before you start, decide on a specific theme or mix of fandoms for your Advent calendar. Here are a few ideas: Single Fandom: Focus on one favorite fandom, like Harry Potter, Marvel, Star Wars, or Pokémon. Multi-Fandom: Mix it