1) Focus on service, not just drinks.
You are a bartender, not an artist - you provide service above all else. If customers have a good experience from a very engaging, attentive, and accommodating service staff but the drinks aren't amazing, they are still likely to come back. Meanwhile, I'm sure we can all name a bar with fantastic drinks but bad service or a pretentious atmosphere that we never intend to visit again. Keep your drink-times quick and always have one eye on your customers.