Crush the ginkgo extract until it's mushy (paste-like, smooth out those bumps!), then add juice squeezed from the bilberry into the mixture. Stir counter-clockwise for two minutes. The bluer it looks when you're done, the better. If you perform a cooling charm on the mixture, you'll most likely feel the healing effects sooner than without.
Use twice, then owl me in the morning if you need a refill. If you find yourself with an excess of bilberries after treatment is no longer needed or you've run out of ginkgo, do not hesitate to make yourself a pie.