Don’t post on social media, especially under your real name.
This includes posting when you’ll be out of the house (I.e. vacation), or the details/names of family members.
Run an adblocker with strict tracker protection on every device you use, and opt for the web version of a product, rather than an app.
Use aliases and throwaway email addresses to anything that requires an account. If they end up being something you use, and are required to provide real information, move forward with caution.
Really, though, the worst thing you can do is post on social media.
Tech companies only care about making money. If people continue to buy their half-effort products, then they’ll keep making it.
On the other hand, open-source (hardware or software) is designed for maximum longevity.
Unfortunately, the wrong people have unlimited resources when it comes to making our tech products.