Whisk the baking soda, citric acid, cornstarch and Epsom salt together in a large glass bowl. Drizzle the melted coconut oil over the baking soda mixture and work it in with a fork until the mixture looks sandy. Add the tablespoon of water a tiny bit at a time, mixing well after each addition. I’ve found that it’s easiest to mix with your hands at this point. If you add the water too quickly the mixture will foam up. After you’ve added a full tablespoon of water, squeeze the mixture with your hand and see if it clumps. If it does, you’re ready to move on. If not, add the reaming water a little at a time until the mixture clumps when squeezed.Add the Lavender Young Living Essential Oils and mix well. For multi-colored bath bombs, separate the mixture into two or more bowls and color as desired. Mix in well.Fill the bath bomb molds to create the desired pattern. Smash the mixture in well! This is key to creating a firm bath bomb. Slightly overfill each half of the bomb mold, hold over a bowl, and work the two halves together. Let the bomb set for at least 15 minutes and up to overnight before removing the bombs from the mold. Place bath bomb on a flat surface to dry for 24 hours. When ready to use, fill up the tub, drop in and enjoy!