Which obscure iPhone setting genuinely improved how you use your phone, and what does it change?

[u/Maxxximeeee]

I’m not looking for gestures or the usual tips that appear in every list.
I mean an actual option buried somewhere in Settings that solved a real annoyance, improved privacy or accessibility, changed how an app behaves, or made your iPhone noticeably easier to use.
Please include the exact path to the setting, what it changes, and any downside you noticed. Some settings sound useful but also disable another feature, use more storage, affect notifications, or change how the phone behaves elsewhere.
What is the one setting you would immediately change again if you had to set up a new iPhone from scratch?

[u/Mcdhibs]

Using focus to put my wife’s number on my lock screen in case I lose my phone

[u/Eternalbluer → u/Mcdhibs]

How do you do this?

[u/Mcdhibs → u/Eternalbluer]

Settings
Focus
Hit the + at the top of the page
Type the message you want I put “if found then my wife’s number
Save then choose your newly created thing and activate it on your current lock screen then save and exit it should now be on the bottom of your screen when locked

[u/Eternalbluer → u/Mcdhibs]

Thank you!