In a large bowl combine baking soda, citric acid, cornstarch and epsom salts.
In a small bowl combine almond oil, water, essential oil, and food coloring.
Pour wet mixture into dry mixture. Mix with a whisk until fully combined. Use your hands to press bath bomb mixture into mold.
You can use the ornament balls I mentioned above or make creative shapes with baking molds. I used a silicone snowflake mold from Amazon for mine. Tip: carefully press the mixture into the silicone mold, try not to press too hard to avoid having the mold widen and distort the design. I let the ornament balls set for 2 hours before removing the plastic ornament ball, then setting them on a towel to dry overnight. For the snowflake mold I let them dry overnight. The dry time will depend on the humidity in your area and home.