It's better with a shot of strong apple jack or apple brandy, but I agree, premixing drinks and bottling is a poor use of time and only limits your options. The novelty of a bottled cocktail wears off pretty fast.
I love using a bottle of my ginger beer, mixing it with ginger infused vodka, and adding fresh lime juice. Moscow mule maybe? I dunno, but it gives me a chance to use copper mugs and feel fancy while at the same time making SWSMBO happy.