Not a particularly well-known method of making hash, dry ice hash has proven to be superior in both quantity as well as quality. It is extremely cost-effective and is perfect for growers who want to put their trimmings to use. You will need a bubble bag, a can or other container with diameter just smaller than the bubble bag's opening (a coffee can is usually about right), dry ice, large flat mirror or glass pane a hash press (not mandatory) and at least 1 ounce of trimmings.

First, place a piece of dry ice (about the size of a computer mouse) in your can or container. Place your trimmings and/or buds in the can on top of the piece of dry ice. Next, place a second piece of dry ice (about the same size) on top of the trimmings. Now, secure the opening of the bubble bag over the opening of the can and make sure it fits tight and secure. You will want to get the can as far into the bag as possible. Turn the can upside down so that the filtered screen on the bubble bag is over the center of your large glass pane. Begin to shake the can/bag directly over the glass. 

After about 30 seconds of shaking, you will notice a layer of kief begin to accumulate on the glass. Keep shaking for 5 minutes. After this, stop shaking and remove any remaining chunks of dry ice from the can. Scrape the kief into a pile and place in your hash press. A hash press can be purchased at any head shop (just be sure to ask for a pollen press). When pressed, this kief will become hash. You may also press it using paper by folding it and using your hands and body weight to firmly press the kief into hash. To get a lesser grade of hash, repeat the process with the trimmings you used the first time. You won’t be disappointed with the amount of hash you can get out of these buds/trimmings.