Use a whitelist-based extension such as NoScript: https://noscript.net https://noscript.net You can then enable just enough JS to make sites work, slowly buil

Use a whitelist-based extension such as NoScript: https://noscript.net https://noscript.net You can then enable just enough JS to make sites work, slowly building a list of just what is necessary. It can also block fonts, webgl, prefetch, ping and all those other supercookie-enabling techniques. The same with traditional cookies. I use Cookie AutoDelete to remove _all_ cookies as soon as I close the tab. I can then whitelist the ones I notice impact on authentication. Also, you should disable JavaScript JIT, so the scripts that eventually load are less effective at exploiting potential vulnerabilities that could expose your data.