Like another poster said, it’s easy to NOT start gossiping, but it’s hard to walk away when someone else has started because 1. it feels rude and 2. the gossip is usually fun. I am trying to form a habit of pointing out the positive possibilities instead of focusing on the negative, thus derailing the gossip while still being conversational and pleasant. It’s something my mom does, and I think it’s a great techhnique. Here is a basic, silly example:

Gossiper: Ew, her hair is awful. Does she ever WASH it?
Possible negative response: Yeah, dude, it’s all greasy and gross. I can’t believe she came to the office like that.
Preferred positive response: Well, maybe she woke up late today and didn’t have time. I know I’ve done that before, and my hair looked worse than that!

It’s kind of a silly example, but the point is that you don’t really KNOW about people’s inner lives and you should give them the benefit of the doubt. This is really hard, but I’m going to try!