Use a password manager, a spam email address, uBlock, pay attention to app permissions... Don't rely on algorithms shaping what you see from the world and confining you in a filter bubble. Have some secrets you don't share with everyone. Be aware of things and learn about the platforms and software you use often, and what they do behind the scenes. Also be aware of alternatives and free and open-source software. Don't give away your identifiers to everyone (phone number for sign-up, credit card number, real name and address, ...)