How do you make an emoji of yourself on iPhone?

You need to use the Animoji menu. To use Animoji, you need an iPhone X or newer.

Open the Messages app, then start a conversation (or open an existing conversation). Tap the Animoji button--it looks like a monkey.

The phone will pull up a bunch of Animojis, but that's not what we're after. Tap the “plus" icon on the left of the Animoji choices. Here, you'll be able to create your custom emoji; you can choose a skin tone, hairstyle, eyes, brows, freckles, nose, lips, ears, eyewear, facial hair, and headwear. Needless to say, you'll spend a lot of time in this menu.

After you've finished, tap the “Done" button in the upper-right corner of the display. You can now choose your custom emoji from the main Animoji menu. Customize it further by adding stickers or tracking your facial movements.

Looking for something simpler? You can also use third-party apps to create emojis. Popular options include Emoji Me Animated Faces and Bitmoji. Both are free (although Emoji Me Animated Faces has in-app purchases). They'll ask for full access to your phone in order to control your Messages app, so keep that in mind when installing--if you don't grant proper permissions, you won't be able to use their keyboards.

One more note: If you use a third-party keyboard, you may have to enable it in your Settings menu. Head to Settings, then tap General, then Keyboards. Tap Keyboards once more, and you'll be able to choose the keyboards you use for text entry fields.