It's all about making a relationship with your customers.  How you do this depends a lot on the way you present your business.  You can do specials, cook to order, meal deals, friendly service—  whatever it is, make sure it fits you and the way you work.  Insincere never plays well.  Then make sure your staff are on board and you never back off it.  Consistency pays.

That said, front-of-house staff are critical   They are how almost everyone knows your restaurant.  Put a lot into training them, making sure they are up to speed, and letting them know you care about them.  Make sure they treat everyone right.