What are the skills and knowledge you could actually bring & fully realize at some point in the past?
And we’re taking this in the strictest, nerdiest, materialist lense. I don’t care how smart you are you ain’t making a steam engine the in bronze age, for instance.
So what could you create, with just your knowledge & period tools? What kind of institutional, technological, philosophical innovations could you realistically recreate? How would you interface with the social fabric of society to not be some crazed pariah who never positively influences the place they went?
Math, some simple tools like 19th century plows, better crop rotation and artificial selection, 17th century and later metallurgy. Basic but useful electricity, a motor can be made from wire and magnets.
Much much better medicine. I can definitely recreate penicillin and gramicidin, ether, basic surgery. I can make small amounts of aluminium, also a map of accessible high yield ore deposits.
Once super rich steam engines and telegraphs and better ships become possible, but the trick is giving people what they actually need and avoiding the “man who came too early” scenario.