Would it be worth the effort to set up some kind of "mixer" service, where your requests will be routed through random other people's accounts? The goal is to destroy the information value of your search history: "Yeah, I searched for horse costumes, but so did everyone else in the pool!"

Probably would be easier just to use an anonymous account for every search, but is it easy to destroy all the patterns associated with the searches that would indicate it's the same person.

(The concept is similar to those proxy services out there that pay people to let them use their "good" IP address to e.g. scrape sites that will otherwise automatically block "obvious" server farms. Also Bitcoin mixing pools.)