Essentially you take an empty bottle and add a certain kind of alcohol to it. Whiskey, gin, scotch, etc. work well. Then as you finish other bottles of the same kind of alcohol, you add the last few pours into the Infinity Bottle.
Over time you create your own blend that changes as you keep adding different flavors to it. People create lists of the alcohol added to it, and because you never let it run out; you'll always have a tiny bit of all the different pours still in the mix.
This longevity gives its namesake, and some have turned it into a sort of family heirloom over time.
Has anyone tried this? Have tips to get started? 
But I have to admit I've not thought of it for liquor. Seems it could go pretty badly wrong over time.
--Satan, quoted by John Milton
In a move that surprised no one, he wound up pissing down the heater of the hotel room at some point in the middle of the night. 
Under capitalism, man exploits man. Under communism, it's just the opposite. - John Kenneth Galbraith
