Expert Bar Customer Service Tips:

Be Friendly - Expert Bartenders are expected to be pleasant, friendly, smile and say "Hello"

Serve Ladies First - When serving a group serve the ladies first.  The courtesy provides them the feeling of being special. 

Carefully and Loudly Count Change - When a customer gives you a bill larger than a single dollar, call out the denomination of the bill.

"That's $3 for the beer out of a $5."

"It's $17 out of this $50 bill?"  

Sometimes  a customer may think they gave a larger bill or smaller bill than they actually did. When making change, leave bill from customer on the tray of cash register until you have made proper change. As you give change count it out loud.

Don't get involved in Controversy - Polititics, religion and social issues should never be discussed by the bartender.  Even though you may discuss a point that both you and the customer agree on, many other customers sitting at the bar ma overhear you and disagree.  Hard feelings are easily cause and enemies easily made without noticing or knowing it. Expert Bartenders keep their opinions to a bare minimum or to themselves completely on controversial matters.

Never Argue - Don't argue with a customer about anything, even if the customer is wrong. Don't argue with fellow employees either.  People are at the bar to relax not listen to arguments.

Definitely Play Favorites - If someone tips well, pay more attention to them and likely you'll be rewarded further. If someone does not tip well or routinely high maintenance it's natural their sense of priority decreases during your busy times.

Be Neat - Your duties as a bartender will include keeping your bar spotless and dry.  Give the customer a dry napkin with every drink.  Immediately remove empty glassware or any mess left behind by customer and keep your area as unclutterred as possible.