i have a grinder with no screen and a little storage thing on the bottom. i put shake in the storage thingy and shake it up a lot. then i pour the weed back in the bag and the edges of the storage thingy are covered in kief. shit i can put shake on my mouse pad(which is plastic), pour it back in the bag and viola, kief on the mousepad. you dont need a special grinder to get kief, just if you want a lot fast.