You're in the middle of a meeting and your phone starts vibrating. It's your mom calling, but you definitely can't talk right now. Instead of just declining or silencing the call — and forgetting to call your madre back later — there's another super-useful way you can handle the situation.
Just above the decline button on the homescreen is a somewhat discreet-looking button: Remind Me. Tap this and you get three options: to be reminded to call back that contact when you leave your current location, when you get home, or in an hour. Select one of these and you can rest assured that you won't forget to call your mom (or whoever it was that phoned you) later that day.
Alternatively, there's another button you can press, Message. Pressing this gives you the option to automatically send this person a text message in lieu of answering their call. You can select from one of three preset options, such as "Sorry, I can't talk right now" or "I'm on my way." Alternately, you can write out a custom message of your own. To do this, go to Settings, Phone, and tap Respond With Text, and then you can swap out a preset with the message of your choice. Your message will then show up the next time you tap that Messages button when you get a call.
Who would have thought that such a convenient solution was sitting right in front of your nose this whole time?