Alright bro. here's the trick....
Most hard liquor is 65 cals an ounce. Just mix your hard stuff, with diet drinks..such as coke or tonic water.
If you're a lightweight...mix your drinks weak. Put 1.5 oz of hard liquor and ice, in a 16oz glass fill with diet mixer of your choice
vodka and diet tonic water and a lime
whiskey, I prefer bourbon and diet coke
Those low cal beers taste like piss water.
If you don't booze much, what ever you do don't get in a drinking comp with a hard boozing SOB...you will lose and feel awful the next day...