Some of you may know this method, some of you may not. But go put your metal 4+ piece grinder in the freezer for 30 minutes, or however long you want to. It's a good idea to simply leave it in there when you are not smoking. Make sure it's got all the parts on it to prevent condensation on the inside, and I would also advice you to take out any bud that is in there. When you grind up your weed after at least 30 minutes, you should notice a significant difference in kief. Enjoy!