Lemon: "Lemon oil can be used not only to detox the body but it can also help with acne,” Scarpelli said. If you want a healthy boost in alertness, a bit of lemon oil mixed 50:50 with a carrier is a great way to give your head a lift. Because of its uplifiting properties, lemon essential oil is also good for increasing focus and concentration. As a bonus, it can help keep fleas away when used on your pets.