(sadly) do-not-track also doesn't work - it makes you stick out even more when activating it. best is to try to blend in with aggressive hardware compartmentalization. there are no solutions that can easily be recommended to somebody less tech-savvy which would protect them from bad actors (and GDPR or not - there will always be plenty of them).
Well, Firefox for one does things to help against tracking. Surely not all the things that can be done, but at least the ones they figured out to be worth it for everyone.