How's it going is a commonly used greeting that most often means, "how are you doing?" There are several synonyms for how's it going, such as "what's up," "how are things," or "what's new?" These greetings are more casual than saying, "how do you do?" or "how are you feeling?" which are more formal. Another way to greet someone is to say, "how's your day going?" or "how's your day been?" These greetings are appropriate for people you know well and are less formal than the previously mentioned greetings. No matter which greeting you use, it's important to show interest in the other person's well-being and engage in conversation.