this guy knows. something to think about : the more kief that falls off, the less potent your actual herb is. when you use the nickel (or dime, depending on size of grinder) the weed you have ground up will get you less high. Personally, I like to put the coin in after I have ground up my weed and after I have removed the ground up weed from the grinder. Once the coin is alone in the chamber, shake the grinder vigorously. This will cause the kief that is stuck to the screen/sides of the screen/sides of the chamber to fall to the bottom of the kief catch. In my opinion, this is the best way to maximize your kief without minimizing your buds. Stay high, friend.