Highest proof alcohol you can get. It should be at least 90 proof, though 151 or Everclear is preferable.
Thoroughly dry and grind 4 grams of cannabis.
Bake the plant matter at 240 degrees in an oven-safe dish for 20-30 minutes to decarboxylate it.
Submerge the plant matter in 2 ounces of high-proof alcohol, stir, and cover tightly so that the evaporating alcohol cannot escape.
Let sit for 3 hours in a cool, dark place. The longer it sits, the more potent it becomes.
Stir the brew again, then funnel through a double-thick layer of cheese cloth, collecting the liquid tincture in a jar.
Pour the liquid through the cheesecloth a second time, again capturing it in a jar for later consumption. Bottle the tincture in opaque, brown or blue bottles as soon as possible to avoid exposing it to light.