I think a proportional representation system applied to state electoral votes would be worthwhile.
For instance, in CA in 2016, Trump got 31.62% of the vote. In our system, that means Hillary gets 55 electoral votes. In a reformed PR system, she would get 34, Trump would get 17, and the last would be split among libertarians and greens.
I wonder how the election would have played out entirely in this system. But it would certainly make your vote more worthwhile and allow legitimate campaigning in every state, regardless of whether it's republicans or democrats. I feel like this is a type of moderate reform that would work well, especially with large states that are considered "safe" for republicans or dems, but it doesn't turn our entire system into some radical system where parties can come together to exclude rising wings that move parties forward—which is necessary, I think, especially given it's tempered by the FPTP system which preserves conservative (in the literal sense) gridlock. Our country isn't built to move radically in a short time period. It's built to be slow and only let the most popular novel movements take shape electorally.