I use Exodus Privacy [1] to learn more about what SDKs and permissions are used by the app before even installing it, and as a last line of defense, NetGuard [2] which is an open-source VPN-based firewall that lets you block requests to some servers on a per-app basis (some features are paid).

[1] https://reports.exodus-privacy.eu.org/en/

[2] https://www.netguard.me/