Michael Busuttil: You’re in charge of doing for DC what Kevin Feige did for Marvel. Go.
Avoid Superman and Batman; DC’s problem is that nobody else comes close to Superman and Batman and they need to push their smaller properties. (Green Lantern was a failure in execution, not a failure in concept.) Start with the Flash, who does not yet have a bad movie and does not need a reboot. Then do Aquaman (and hopefully at this point we do not have to explain why Aquaman is actually totally badass). Then Wonder Woman in the Thor slot. Then you reboot Green Lantern properly, and probably have it be John Stewart instead of Hal. In each of these movies, the connecting thread is J’onn J’onzz, who appears in each movie as a different person because he is a shapeshifter, which also lets you have J’onn be played by whoever in the Justice League movie you’re aiming towards.
Probably you can squeeze Flash #2 in there somewhere so Wally is properly ready to be the Flash, and only then do you do your Justice League movie. Probably with Starro as the villain, because Starro is a League-caliber threat and because it’s a nice nod to the comics and also I think a giant fucking space starfish would work wonderfully onscreen. But you can also probably fit Lex Luthor in there somewhere, because come on, it’s Lex Luthor and he is the best villain ever.
The key difference here from the Avengers template is that, unlike in Avengers, your biggest comic properties in DC are very much core to the team. You can do the Avengers without Spider-Man or Wolverine (and many argue that you should). But doing Justice League without Superman or Batman will not quite work.
So this is how we fix that. Somewhere off to one side a bit, there’s a Superman movie. Don’t explicitly acknowledge it as “new DC movieverse canon.” Have Superman fight baddies in space, he’s good at space. And then in Justice League just when the baddies are going to win about halfway through, that is when Superman makes his big entrance. As for Batman, there is no Batman movie, because in the new DC movieverse, Batman Is A Myth until the Justice League movie when he shows up and people are all “wait, you’re real?” This was a cool idea when DC first used it, so let’s steal it. And it lets your big movie coming out of Justice League be the next iteration of Batman, which will give it a respectful distance from the Nolan trilogy.
That’s how I’d do it. The only issue is that this Justice League only has one woman on it, which has always been a problem with the team. Maybe you can replace Aquaman with Zatanna, who is the only DC female character who I think can justify a movie other than Wonder Woman right now. (Hawkgirl won’t quite work, sorry.)