I don't think you can craft a strategy to increase voter turnout very much. That's a much larger function than any campaign or even party committee can perform. That has more to do with politics as a whole and what's happening in the country, and it's hard to even analyze. Obama was a perfect turnout candidate, coming on the heels of an unpopular Republican and brought tons of disenfranchised black votes to the table. But even that was probably just a novelty, as turnout dipped again in 2012.
How do you get voters to turn out and support your candidate? Even 2016 didn't have high turnout, and that was circus level stuff.
On the other hand, 30% of the country are "Independents" and a lot of them live in swing states, and we know what their concerns are. Sanders brings some enthusiasm from the non-voting youth, which is good, but he also walks a tightrope in the states that decide the election, between capitalism and socialism. And his opening-the-factories rhetoric there has always seemed unrealistic, in addition to the single-payer talk, which isn't actually as popular as some people think (strongest support is for the option), and how the question is answered in surveys depends a lot on the framing of the question. Needless to say, the people we have to appeal to in order to win are not fans of being kicked off their insurance - one of the last remaining solid benefits out there - against their wishes.
