This guide will be primarily for the United States. If I refer to any such laws within this country, please check your national laws for anything equivalent.
You have an Android phone. You want to free up storage. You want to conserve battery life. You want to remove all of that artificial "intelligence" slop from your phone. You want to be more private and secure without the lead developer of a certain security-hardened Android ROM and his ignorant, Kool-Aid drinking simps raging after you and then using DARVO tactics to gaslight everyone else into thinking you're the ones harassing them. Regardless of how you look at it, stock Android can be a bloated, convoluted mess out of the box. You've come to the right place.
Let's start with setup. Don't set up any TouchID or Face Unlock. While lock screen passcodes and passwords are protected under the 4th and 5th Amendments of the United States, that is not true for your face or your fingerprints and law enforcement can hold your phone up to your face to unlock your phone or force your finger on the fingerprint reader.
You'll want to check the permissions on each and every single app you have that you didn't uninstall using my Debloat Guide. For example, on my own Pixel 10 I still have the main Google app on my phone and I made sure to remove permissions for Calendar, Contacts, Call Logs, Camera, Location, Microphone, Phone, SMS, and Photos and Videos because I hardly ever use that thing. I still have Nearby Devices allowed because sometimes I do need it to talk to other devices I have, but I have one trick to keep it from running in the background despite Google's best efforts: I've turned off "Allow background usage" under App battery usage and turned of Background data under Mobile Data & Wi-Fi. Go through each of your apps, including the ones you downloaded, and make sure you revoke permissions you don't want it to have. Why does a default calculator app need your location? Revoke that (the stock Calculator app on Pixels don't use any permissions whatsoever, this is in case OEMs like OnePlus sneak that permission into parent company Oppo's calcuator app or something).
There are a LOT of things to toggle in your main Settings. If you can't find anything I'm talking about, use the search function. All of these settings are in Samsung Galaxy phones but OneUI hides them in weird places.
First of all check to see if you can disable 2G under Mobile Network. 2G bands are what Cell Site Simulators a.k.a. Stingrays use to intercept cell phone traffic, and the data transmitted under those bands is often unencrypted. If nothing else you can make your preferred network either 5G or 4G. They're both a bit more secure.
If you've followed my Debloat Guide then you've already done this step, but enable Developer Options by going into About Phone and tap Build Number 7 times. Then go into Developer Options, Quick Settings Developer Tiles, and toggle on Sensors Off. This will disable your camera, microphone (unless you're making a phone call), gyroscope, and accelerometer. This makes it a privacy focused kill switch. If you need a navigation app, toggle Sensors On back off through Quick Settings and not Developer Options.
Go into Security & Privacy, go into Privacy Controls, select Ads, and delete your advertising ID. It should go without saying what one of these is. After that, go into Device Unlock, Screen lock, and select Enhanced PIN Privacy. This will stop each key from being highlighted as you enter your screen's unlock code if you selected a PIN.
Disable "Customize the experience using your Google Account data" under Android System Intelligence after hitting "Clear data."
If you trust Google completely and have no intention of sideloading apps from F-Droid or Obtainium, then go ahead and enable Device protection under Advanced Protection. This functions in a similar way to iOS's Lockdown Mode.
Going back to your apps, it's important to use the right kind of apps. Obviously for instant messaging I recommend using Signal or Session. You can also look at my Recommended Apps page for more details.
This will be updated in the future, but if you've followed my above steps then you're far better off than most other Android users.