The keg-shake method
What I DO NOT recommend is the keg shake method for those that are impatient and want to drink their beer immediately after kegging. Though I agree that this rivals any kettle-bell workout, it ultimately yields terrible results.
As you most likely are, I am impatient too as I started cranking out batches. Blitzing the pressure to 40 psi, shaking, backing if off, shaking, shaking and shaking until it holds at around 10-15psi will carbonate it, but upon tapping you will have pure foam.
The ‘let-it-relax’ method
What you want to do is first, consult a pressure/volume C02 chart, figure out what volume of C02 your beer needs per the style, set your regulator to that pressure. Make sure the top of your soda kegs are not bleeding C02. Close the door to your refrigerator and don’t come back for a week. Your beer will then be nicely carbonated, or almost done.
I have been doing this method for nearly a year and if you are brewing regularly, you will never be out of beer and impatient for the next one to be ready.
So just set your regulator to 14 psi, put it in a refrigerator at 45 degrees and let it sit for a week. That’s it. This will work for most styles.