How to use Essential oils for skin care: Tea Tree essential oil can be used directly on the affected area for spot treatment. It is best to lightly dab it very gently on the pimples. This should be applied at the end of the skin care routine, and preferably at night. Carrot seed essential oil needs to be diluted in a base oil such as argan, almond, etc., before applying to skin. One recipe for skin lightening is to add 5-10 drops of carrot seed essential oil to 2 table spoons of argan oil. 5 drops of lemon essential oil can also be added for skin lightening serum. Dilute Geranium essential oil in a base oil or face cream in 1-2% ratio, and apply to the face 2 times a day. Frankincense and Lavender essential oils can also be added to this for added skin benefits such as anti-ageing, skin rejuvenation, youthfulness, etc. It is advised to use base oil which is cold-pressed, and is free from chemicals and mineral oil.