Use a Brow Serum
Brow serums are all the rage and for good reason; products like these noticeably speed up brow growth in a matter of weeks. While products like BROWFOOD have a thin brush tip for tending to the spots your brows that need to be filled most, products like RapidBrow and RevitaBrow use a spoolie applicator and a doe-foot applicator, respectively, for all-over brow coverage.
[Photo via @lashfood]