Absolutely nothing at all. I do not mind being tracked, all that happens I get targeted (better?!) ads for it. If I'd have something to hide, it's the government I would want to hide it from, not corporations. And you can't really hide from the government...

That being said I do run ad&popup blockers for a better browsing experience. Those idiotic cookie prompts are the bane of web browsing inside the EU and I run the "I don't care about cookies" extension to get rid of them.

I also encrypt sensitive private folders on all my machines.