Are you on Android? Use Firefox with NoScript or uMatrix (also as your default webview) and setup AdGuard DNS [0] or a pi-hole. You could consider using a VPN like Orbot (free Tor-as-a-proxy) [1], PerfectPrivacyVPN (supports multiple exit IPs, multiple-hops, and server side firewall) or set one up using Algo/Streisand [2].
If you do not want to root your device:
1. Install NetGuard or No Root Firewall to view what's going on from network perspective.
2. Install ExodusPrivacy to generate a report on apps wrt sdks in use by them.
---
If you are okay to root the device:
1. Install XposedMod, and then XPrivacyLua module, and work through the options.
---
If you're okay with flashing a ROM:
1. Consider LineageOS + microG
2. If you are using Pixel, consider ChromeheadOS (edit: CopperheadOS) [3].
---
If you're okay with a new device:
1. Consider purchasing puri.sm Librem 5.
---
[0] https://news.ycombinator.com/item?id=18788410
[1] https://guardianproject.info/apps/orbot/
[2] https://github.com/trailofbits/algo
[3] https://copperhead.co/android/
If you do not want to root your device:
1. Install NetGuard or No Root Firewall to view what's going on from network perspective.
2. Install ExodusPrivacy to generate a report on apps wrt sdks in use by them.
---
If you are okay to root the device:
1. Install XposedMod, and then XPrivacyLua module, and work through the options.
---
If you're okay with flashing a ROM:
1. Consider LineageOS + microG
2. If you are using Pixel, consider ChromeheadOS (edit: CopperheadOS) [3].
---
If you're okay with a new device:
1. Consider purchasing puri.sm Librem 5.
---
[0] https://news.ycombinator.com/item?id=18788410
[1] https://guardianproject.info/apps/orbot/
[2] https://github.com/trailofbits/algo
[3] https://copperhead.co/android/