Use around 2-3 Tbsp. per load of laundry
The baking soda and washing soda help loosen the tougher stains and dirt and remove odors; the essential oils will add a nice smell and in some cases, they will also be beneficial to your fabric. (Certain essential oils like eucalyptus and lemon are known to help remove grease stains.)
It's best to use gloves while working with the washing soda as it can irritate your skin.