I use a spatula to roll my buds around on the screens. Keeps them from matting down and possibly getting mold. I tried shaking the screens or tapping the bottom and just ended up flinging smaller buds all over. I also put a washing machine tray with a fan in it below the rack. It catches all the debris that falls through the screen. Most of my flat bud comes from the buds being to dang close on the plant when it grows though.