Don’t offer new customers something you wouldn’t offer your loyal customers.
Be accountable when providing customer service to new customers. It’s about providing value to the new experience. The server/bartender knows the ins and outs of the front operations. They should know the best way to provide the best possible experience for any customer: new or returning. By cutting corners and not offering the best possible service or products, it de-values the customer and personal improvement.
Similarly, make sure the new customer gets the amazing experience they deserve. They are taking their own time out to spend their money at the restaurant/bar. It is not required of them to do so; so make sure they get the best possible value.
If there is a popular drink or menu item that is unique to the restaurant, offer it to the new customer. If there are things that returning customers tend to enjoy, offer that to the new customers. The experience of the new customers is important. Their one experience will determine if they will come back to the restaurant or not. So it should be memorable.
Where was your favorite first time visit to a restaurant or bar? Why was it?