Phone Settings Worth Changing on Day One

New phones ship with defaults chosen for demonstration and for the manufacturer's interests. These are the ones worth changing, in roughly the order of how much difference they make.

Privacy and permissions

Review app permissions by permission, not by app. Settings, Privacy, Permission manager. Look at Location, Microphone, Camera and Contacts and see which apps have each. This view is far more revealing than checking apps individually, and it routinely finds something unexpected.

Set location to "while using" rather than "always" for everything that does not genuinely need background location. Very few apps do.

Turn off precise location for apps that only need your general area — weather, news, shopping.

Disable advertising personalisation. Settings, Privacy, Ads. Also reset the advertising identifier, which severs the link to your existing profile.

Turn off usage and diagnostics reporting if you would rather not send it.

Check the microphone and camera indicators are enabled, so you can see when something is using them.

Lock screen

Hide notification content on the lock screen. Settings, Notifications, then the lock screen option. Choose to show notifications but hide sensitive content. Without this, anyone glancing at your phone sees your messages and, importantly, your one-time verification codes.

Disable the voice assistant from the lock screen, which can otherwise read and send messages without unlocking.

Restrict the quick settings panel when locked, so someone cannot enable flight mode to prevent you tracking the phone.

Set the screen timeout to something short, with a lock delay of zero.

Battery and data

Set app auto-updates to Wi-Fi only in the Play Store. The single biggest source of unexpected mobile data use.

Turn on adaptive battery and adaptive charging if available.

Check background data per app for anything heavy you do not need updating constantly.

Set a data warning and limit in Settings, Network, Data usage.

Turn off Wi-Fi scanning and Bluetooth scanning when off, in Location settings. These allow scanning for location purposes even when the radios are switched off, which is rarely what people expect.

Storage

Turn on the storage manager to remove backed-up photos automatically.

Check what is actually large. Settings, Storage. It is nearly always photos, video and one or two apps with large caches.

Disable manufacturer bloatware you will not use. Settings, Apps, then Disable. Many preinstalled apps cannot be removed and can be disabled, which stops them running and updating.

Notifications

Go through them once, properly. Settings, Notifications, App notifications, sorted by most recent or most frequent. Turn off everything that is not a person contacting you or something genuinely time-sensitive.

This is fifteen minutes and it is the highest-value fifteen minutes on this list for daily quality of life.

Set up do not disturb with exceptions for starred contacts and repeat callers, so genuine emergencies still reach you.

Display and comfort

Reduce the refresh rate if battery matters more to you than smoothness.

Set up the blue light or reading mode schedule.

Adjust font size and display size — these are separate settings, and display size is the one that makes interfaces genuinely more usable for anyone with imperfect vision.

Turn off the always-on display if battery matters.

Security

Set a six-digit PIN or a password, not a four-digit code or a pattern.

Enable two-factor authentication on the account tied to the phone.

Turn on Find My Device and verify it works by locating the phone from a browser.

Set up emergency information and contacts on the lock screen.

Record the IMEI somewhere other than the phone.

What to check that is not a setting

Where your two-factor codes live. If they are on this phone and nowhere else, store the recovery codes elsewhere before you need them.

Whether your backups are actually running. Photos, contacts, messages, and any app with data you would miss. Check the last backup date rather than assuming.

Which accounts are signed in. Settings, Accounts. Remove anything from a previous owner or an old account.

The five-minute version

If you do nothing else: hide notification content on the lock screen, set app updates to Wi-Fi only, review location permissions, enable Find My Device, and store your two-factor recovery codes somewhere off the phone.

Mistakes people make

Checking permissions app by app. The permission manager, viewed by permission rather than by app, shows who has your location and microphone in one screen, and routinely finds something unexpected.

Leaving "always" location on apps that only need it while open.

Leaving notification previews on the lock screen, which displays message content and one-time codes to anyone holding the phone.

Not turning off Wi-Fi and Bluetooth scanning. These continue scanning for location purposes even when the radios appear to be off.

Assuming backups are running. Check the last backup date rather than trusting that it is configured.

Force-removing preinstalled apps. Disabling stops them running and updating, and is reversible.

The short answer

Hide notification content on the lock screen, set app updates to Wi-Fi only, review location permissions in the permission manager, enable Find My Device, and store your two-factor recovery codes somewhere other than the phone. Five changes, five minutes.