Line a 10x15-inch pan or cookie sheet with wax paper.
Place chocolate chips or melts in a microwave safe bowl. I like to use a disposable paper bowl or re-usable plastic container for best results. Add shortening or oil if using chocolate chips. Heat on 50% power in 30 second increments, stirring between each, until melted and smooth.
Spread chocolate into an even layer on the prepared pan. Top with desired toppings. Chill to set then break into pieces.
Peppermint White Chocolate Bark: Sprinkle chopped candy canes or peppermint crunch over melted white chocolate.
M&M Chocolate Bark: Sprinkle holiday or any flavor M&Ms over melted white or regular chocolate.
Oreo Cookie Bark: Sprinkle chopped chocolate chip cookies and/or Oreos over melted white chocolate.
Peanut Butter Cup Bark: Sprinkle chopped peanut butter cups over melted milk or semi-sweet chocolate.
Caramel Pretzel Bark: Sprinkle chopped pretzels and Rolos over milk or semi-sweet chocolate.
Almond Toffee Bark: Sprinkle almonds, toffee bits, and cocoa nibs over dark chocolate.
Peanut Butter Swirl Bark: Heat 2 tablespoons creamy peanut butter until pourable then drizzle over chocolate and swirl. Sprinkle with chopped peanuts.
White Chocolate Pistachio Cranberry Bark: Use white chocolate. Sprinkle ½ cup each dried cranberries and chopped pistachios over the chocolate.
Reindeer Bark: Place mini twist pretzels in pairs randomly around the chocolate. Add two candy eyes and a red m&m nose.