The traditional method of dressing or annointing a candle required that one began by applying the scented oil in the center of the candle. Stroke up from the middle to the top, and then down to the base.
If you plan to carve sigils, designs, or letters into the candle, these ought to be carved into the wax before annointing the candle.
Most magical herb practitioners insist an essential oil should be "cut" or diluted with a base oil, like olive, almond, sesame, etc. Essential oils are highly concentrated and some, like clove, can irritate the skin if not washed off immediately.
Some recipes for van-van oil contain citronella, palmarosa, and ginger grass, as well as the primary ingredient, lemon grass. Yet, some only contain lemon grass (Cymbopogon citrus) and some contain lemon verbena (Lippia citriodora). Therefore, Van-Van Annointing Oil is sometimes used as an offering to Diana, particularly by modern, eclectic Dianic Wiccans.
Both lemon grass and lemon verbena have a distinctive citrus scent. Lemon grass was said to enhance intuitive clarity. Intuition, of course, is under the domination of the moon. Lemon verbena, which is sacred to Diana, was believed to have the ability to strengthen magical endeavors. As such, it was sacred to Aradia, la prima strega della mondo, first among witches.