To define your shape use a pencil to lightly outline the base and top of your brow. Keep things on the natural side by just outlining the top and bottom rather than all the way around.
It Cosmetics’ Brow Power Universal Brow Pencil is the pick for super defined brows. Suitable for any hair colour (and for those liking to tint their brows, that colour can change a bit between visits to the brow bar!), it can be pressed lightly for the perfect shade for blondes, or heavier for brunettes. The pencil is easy to use, stays in place and adds great definition without looking fake.