IOS 13, Apple's big software update that's now available for iPhones, lets you make fun changes to your Memoji. These are the animated characters that you can send through iMessage and use the front-facing camera to reflect what you're doing.
So, if you say, "Hey, how's your day going?" and smile while doing so, you can record your Memoji doing the same thing, and your facial expression and mouth movements will be sent in the Memoji message to your friend. This existed in earlier versions of iOS, but now you can make your Memoji look more like you with custom hair colors, AirPods, accessories and more.
I'll show you how, but first make sure you've updated your iPhone to iOS 13.
That's it! Tap the "done" button on the top right of the page when you're finished. Now, when you're in a message, just select the monkey icon and choose your Memoji. Tap the face to send a picture, or tap the record button to send a video with audio.