Add these bath fizzies in a jar to your bath time routine for a colorful pick-me-up. Ice-cube trays serve as molds, giving the fizzies their shape. Using a flexible silicone model lets you slide the cubes out smoothly without breaking them. Pack each type of fizzy in a separate jar so the scents won't meld. Write the name of the scent on a vellum tag (choose a shade that matches the fizzies), and punch a hole in the top. Thread the tag with ribbon, and tie it around the jar. Citric acid, a common food additive, is available at wine-making-supply stores, some spice shops, and online. When citric acid is combined with baking soda and placed in water, a chemical reaction creates bubbles. This recipe makes one dozen; we recommend using two per bath.