Your iPhone 11 appears to have locked up. The touchscreen is inoperable. You press and hold the volume and side buttons, but nothing happens. What should be your next action?

If your iPhone is completely frozen, the only thing you can do is power it off and then back on. The specific buttons to hit vary depending on the model, however the technique mentioned in this question is applicable to iPhones X, 11, 12, and 13.