I came up with a voting strategy that I call single issue tactical voting. The idea is that you pick what you think is the single most underrated issue, and announce you will either vote for your major candidate, or third party, depending on whether the major candidate agrees to support your issue. This works around Arrow's impossibility theorem and doesn't require any changes to the voting system. The goal is not to change the outcome of the election (if everyone is rational the outcome will be the same), but to influence the candidate's specific policies.

I was partly inspired by this application of game theory: https://www.youtube.com/watch?v=coWgbmlvRTU

I've been meaning to do a full writeup but hesitant in the current election climate... :)