Create a unique holiday tree with these quick (and compostable) DIY ornaments. First, preheat your oven to 200 degrees and line a baking sheet with parchment paper. Gather a variety of citrus fruits – including oranges, lemons, tangerines, blood oranges, grapefruits and the like – and cut into thin slices (be sure to discard any seeds). Spread the slices across the baking sheet and bake until they are dried out (about two to three hours), being sure to flip the fruit every half hour. Once the ornaments are completely dry and cool, pierce them with paper clips or ornament hooks.