To create a correctly-plucked arch, follow the natural curve of the eyebrow, and be sure that the high point of the arch aligns with the outer edge of the colored part of your eye. Sketch out the shape of the brow with an eyebrow pencil before you begin plucking.
As you sketch the eyebrow, consider your face shape; soft, rounded brows flatter angular faces, while sharply defined brows add dimension to rounder faces. Once you have chosen the shape of the brow, tweeze away stray hairs with a sharp pair of tweezers. Avoid over-tweezing to prevent the formation of bald spots.