You can also make a keef box. A box that has a slide-out mirror on the bottom, and a very fine screen on top(a pair of panty hose). If you break up your buds (when packing bowls or whatever) over this box, the crystals (nothing bigger, anything larger should be filtered by the screen on top) will fall onto the mirror. When enough of these crystals build up, you can slide out the mirror, scrape the crystals off and put them on a bowl. It messes you up.