Tea tree oil is essential for acne sufferers and should be a staple in every cosmetic bag. This natural oil helps maintain healthy skin thanks to its antibacterial, antiseptic, antifungal and toning properties, it is also a popular ingredient in skincare products. When applied to the T-zone area of the face, it can reduce excess sebum, which makes skin oily. It also sanitises pores and dries up blackheads and pimples.