I avoid Facebook, and Instagram, and WhatsApp, and most other social sites. I rarely install any apps on my phone, and when I do, I won’t do so if they expect to use my phone number as an identifier. (The one exception is Signal.) I disable 3rd party cookies in my browsers. I run Firefox with privacy focused plugins that disable scripts and advertising. I make an active effort to remain logged out of Google when not actively using it. (I don’t have accounts with YouTube, despite the nagging, for example.) I do maintain a fake persona whenever possible. The persona has his own email address. Any throw away account for something I don’t really care about is opened in his name. I have no idea if all my efforts are working, but it hasn’t harmed me that I am aware, and if Facebook has a shadow profile for me, it probably is very confused about who I am. If I do see any ads, they’re invariably related to clothes, feel very generic and are very ineffective as that is something I would never buy online.