Perhaps you find it easy to misplace your iPhone -- as I frequently do. One way of quickly locating the iPhone is to have your spouse or someone call your phone number. You'll soon hear a ringing and now can find your iPhone -- unless, of course, you've misplaced it 20 miles away. Then, hopefully, some honest person will answer and tell you where your phone is.
This article points out another way -- ask Siri where is your iPhone? The article explains how. If you have an Apple watch, you can also use your watch to track down the missing iPhone.