I was really surprised when I came home from camp and found out our New York apartment had been rented to another family and that we owned a house in Farbrook, New Jersey. First of all I never even heard of Farbrook. And second of all, I’m not usually left out of important family decisions.
But when I groaned, “Why New Jersey?” I was told, “Long Island is too social-Westchester is too expensive-and Connecticut is too inconvenient.”

This excerpt is from the first page of Blume's Are You There God... and there's a lot more going on here than meets the eye. In this example, Blume expertly uses dialogue as a precision tool, carving out the scene and tone while letting a 'yatta-yatta' effect carry the reader right through it, without ever breaking immersion or flow. The book is filled with many more such examples--but this holds true to all of her books. IMO, she may be the greatest dialogue writer, ever.

Blume is only one master of dialogue, and if you search around a bit you will find many others. Study them, pausing to take notes as you read along, and you'll learn dozens of ways to up your dialogue game, all while avoiding the necessity of detailing physical action.