101 different ways I reckon, a bit of trial and error required.
But if you're in a hurry, chill your corny right down in the freezer, connect the gas, set the regulator to about 20psi, lay it on the floor and rock it back and forth for 15 minutes, turn the gas down and serve.
Planning: A few German style beers
Fermenting: Kazbek pseudo-lager
Drinking: Mosaic Sorachi Ace pale ale, Milk stout nitro, Shop bought stuff