1) Paid VPN - Mullvad is the best when it comes to privacy, cash in mail, no user data necessary to sign up
2) Browser such as chromium, mullvad browser, or potentially Libre. Don’t, DO NOT, use a big name browser. They will track your shit, shit you didn’t even know could be tracked.
3) Don’t ever log in to anything you use for business outside of your vpn connection, basically renders it all useless.
4) Private email, proton or Tutanota will be good for your purposes. There are some .onion hosted alternatives depending on what you’re doing..
5) If you’re more than a buyer, Tails USB, paired with a python USB kill switch is a must. Your operating system will run from the USB (Tails) and your python script will shutdown your PC and wipe your ram when it senses any changes to USB devices, like you emergency unplugging your Tails USB.
6) Use an “offline” or “hardware” crypto wallet. Not your keys, not your coins.
6a) Prioritize XMR.
6b) If you must buy KYCd coins using your information, break the chain of custody before spending them.. or just use XMR.
If you have any questions feel free to reach out, this just scratches the surface.