If you have an ios device, turn off biometrics, turn on adp (actually store your code in a safe place!), turn on lockdown and start aggressively powering your phone off when you’re not using it.
Learn the duress combinations, on iOS it’s the side button five times. From there you can make an emergency call, power the phone off or cancel out and unlock with pin only (no biometrics).
Use this screen to power your phone off so when its confiscated it boots into bfu (before first unlock) state.
https://tools.sendmarc.com/ Is a good start. Listen back through the security now eps where he’s setting up his own email list with his own email server.