I've often fantasized about this but with a view to changing events which have been catastrophic in my lifetime. Taking just two for example, 9/11 and Hillsborough.
I have often wondered how just a normal person armed with nothing but foreknowledge of these kind of events could actually do anything to thwart them. Now the notion of just contacting the authorities in place at the time with a kind of "guess what's gonna happen unless you listen to me and act upon what I tell you..." is something I always discount from my strategies .....for the obvious reasons which I hope most will understand.
Anyway, the trick is to time-travel....influence these events for the better, but leave absolutely no trace of your involvement nor draw any attention to yourself in the process. The plan must also be "do-able" based on what is now known of the facts.
I think with the Hillsborough scenario, I'd be looking to influence the redeployment of Brian Mole which resulted in the appointment of David Duckenfield. Mole was redeployed by SYP because of a prank which occurred and he took the rap. If I could just
thwart that prank....then.....anyway.....that would be my first punt.
You get the idea?
9/11 is a bit more tricky.....[I'm considering the
traditional narrative only here BTW u conspiracy folks ]
Phone in a bomb scare to world trade at 8am ? Would that get both buildings emptied and away from the danger? Mmmmm.....maybe not.
There were a lot of 'moving parts' to 9/11 which would need to be addressed so a lone time traveler would still be severely challenged by the sheer scale of it all and how best to try and thwart it.
You could arm yourself and board one of the planes knowing who you'd need to slot and when....but then...that would just be one plane.....leaving three unaddressed.
[But what the other three then do would probably get you off the hook with what you've just done.....and this breaks the anonymity part somewhat.....]
It's a tricky one....