Easy Homemade Bath Salts Recipe - Garden Therapy **1. Fill each mason jar about halfway full of the Epsom salts. 2. Add just 10-15 drops of essential oil, replace lid, and shake. 3. Remove the lid again, add 1 tablespoon of dried lavender flowers, replace lid and shake (again). 4. Add more Epsom salts to full the jar then (you guessed it) replace the lid and shake shake shake.