So will you not vote at all? Because when there are two possible outcomes, it seems there must always be a preference to be had, even if not ideal. Protest votes, or idealistic votes for marginal candidates can result in your least preferred outcome. Not voting, the same. Better to just squinch your eyes shut and punch that card, pull that lever, whatever.
Also, the presidential decision aside, how do you make your choices down through state and local elections? In much of the country, those elections can actually impact your life more directly than who is sitting in the oval office.