Flat screening removes the trichomes by rubbing the skuff over a fine steel or silk screen. This is a very simple process but the quality of hash is very dependent on the skill and patience of the maker. The principle behind this method is that the trichome heads are of a fairly consistent size, so that when applied to a mesh of the appropriate size, the trichome heads will pass through but other plant matter will be left behind.

You'll need a flat screen. Screens can be bought from printing supply shops for $10 to $30, depending on size, or you can make your own. To make your own, fasten four pieces of wood together to form a frame, then glue screening to the bottom. Small hole screens are best, between 125-137 lines per inch.

You'll also need a piece of glass or a mirror to collect trichomes, a credit card or something similar for pushing, and of course skuff.

Skuff used for flat screening should be dry, but not too dry. If your skuff is really crumbly, too much vegetable matter will pass through the screen.

Put the screen on top of the mirror or piece of glass and place the skuff on the screen. Using the card, gently push your skuff back and forth across the screen. Using minimal pressure on the skuff produces the best hash. The first layer of powder that comes through will be the most pure and potent.

Because the skuff must be in contact with the screen to remove the glands, it is almost impossible to get a pure hash through flat screening. For this reason, some people choose to pass their skuff through an old pair of panty hose or a screen with slightly larger holes first. This produces a mixture of trichomes and small bits of plant material, which is then transferred onto the small holed screen. The screen then only needs to be tapped to let the glands fall through and be separated from the vegetation.

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.