The Firefox Multi-Account Containers extension lets you carve out a separate box for each of your online lives – so Exhaustive Shopping Researcher Self can steer clear of Humble Bragging Social Self, and Super Professional Work Self can go about the bizness without worrying about being followed by those other two.
What a fantastic feature from the Firefox team. I'm unsure "container" is the right word. I may have gone with just "switching" or something. But, either way, I hope Safari makes this easy too*.
* I think Chrome has something akin to this, but I believe it is tied to a Google account. It shouldn't be.