Ten minutes is enough to close the obvious leaks on an Android phone, provided you go straight to five screens instead of wandering through Settings. The order below is deliberate: it starts with permissions, because that is where the widest access sits, and ends with the network-level settings that most guides skip entirely. Paths are for stock Android 14 and 15; Samsung’s One UI 6 puts the same controls under Security and privacy instead of Privacy.
Minutes 0–2: one screen that sorts every permission
Open Settings > Privacy > Permission manager (Samsung: Settings > Security and privacy > Permission manager). This is the single most useful screen on the phone: pick Location, then sort by Allowed all the time. Background location is the permission that drains battery and builds a movement history at the same time, and almost nothing needs it. A ride-hailing app needs location while you are using it; a weather app needs nothing at all. Google’s own permissions help page spells out what each grant actually lets an app do, which is worth a skim before you revoke something that breaks a feature you rely on.
Repeat for Microphone and Camera, where the only sensible answers are “While using the app” or “Don’t allow”. Then check Files and media: Android 13 and later let you grant access to selected photos only, so a chat app never needs your whole gallery.
Minutes 2–4: the advertising ID and activity history
Open Settings > Google > Ads and tap Delete advertising ID. From Android 12 onward this replaces your resettable identifier with a string of zeros, so apps that profile you across unrelated services get nothing usable. It does not block ads; it stops the ad being tied to a durable profile of you. On Samsung the same screen sits under Settings > Google > Ads; typing “Ads” into the Settings search box is faster than hunting.
Then go to Settings > Google > Manage your Google Account > Data & privacy > Activity controls, and set Web & App Activity to auto-delete after 3 months rather than 18. Anything that has to be retained for a service you actually use can stay on; the rest is history you will never look at and cannot easily delete later.
Minutes 4–6: stop the lock screen leaking
A locked phone that shows full message text and one-time banking codes is a phone that has already told the person next to you your business. Set Settings > Notifications > Lock screen notifications > Show sensitive content only when unlocked. Then, for banking and authenticator apps specifically, go to Settings > Apps > [app] > Notifications and set the lock-screen option to Don’t show.
While you are there, revoke notification permission from anything that is not a person, an alarm or a delivery. Every app allowed to post notifications can also draw over the lock screen, and the count creeps up quietly after each update.
Minutes 6–8: camera, microphone and sensors
Pull down Quick Settings and look for the privacy chip — the green dot in the status bar means something is using the camera or microphone right now. Tapping the chip lists the app and offers a block button, which is the fastest way to deal with an app that has no business listening.
For a hard stop, open Settings > Security and privacy > Privacy controls and switch off camera or microphone access device-wide. If you want the sensors dead too — accelerometer, gyroscope, the lot — enable Developer options (tap Build number seven times under About phone) and turn on Sensors off. It kills the camera and microphone system-wide until you switch it back.
Minutes 8–10: private DNS and the networks you keep
Set Settings > Network & internet > Private DNS > Private DNS provider hostname to dns.google or one.one.one.one. Queries are then encrypted and your carrier or the café router stops seeing a list of every domain you resolve. It is one field, it survives reboots, and it catches some tracker domains at the resolver.
Finish by pruning saved networks — Wi-Fi > Saved networks — and disabling auto-connect for anything open. Then turn off Wi-Fi scanning and Bluetooth scanning under Settings > Location > Location services; both keep the radios chirping even with Wi-Fi switched off, and both cost battery. Two related screens are worth five more minutes another day: the theft protection switches that make a stolen phone useless, and call blocking, which handles the other half of the nuisance traffic.