Emoji are useful in text messages because short replies can be hard to read. A simple "ok" can feel cold, but "ok 😊 Smiling face with smiling eyes" usually feels warmer.
People use emoji in texts to show mood, soften a direct message, signal a joke, add affection or replace a short reaction. 👍 Thumbs up, ❤️ Red heart, 😂 Face with tears of joy and 🙏 Folded hands are common examples.
Context still matters. A thumbs up can mean agreement, acknowledgement or a quick end to the conversation. A smile can be friendly or awkward depending on the person and situation.
Good text-message emoji use is usually simple: add emoji when it clarifies tone, and avoid stacking too many if the message needs to be clear. See emoji meanings by context.