There is a rumor that WB will only release one DC film per year. That being said, I think this is how they should build their universe.
2013: MAN OF STEEL: Based on what I have seen, they are doing this film fine. There should be references to Doomsday, Brainiac, Lex Luthor, and Darkseid for future sequels.
2014: GREEN LANTERN 2: This would be a sequel to the 2011 film, but be almost nothing like the first film, besides Reynolds and Strong. The villain could be Sinestro, and there could be a reference to Thanagar and Apokolips.
2015: WONDER WOMAN: This could be sort of like the animated film, with Ares as the villain. There could also be another reference to Darkseid.
2016: THE FLASH: This could be in the same tone as Sam Raimi's SPIDER-MAN, and use Barry Allen. Also, the Rogues could be like a mafia group, so the film could have multiple villains without feeling crammed. There could also be references to Gotham, Metropolis, Star City, etc.
2017: THE BATMAN: This could be a reboot with the origin told over the opening credits, like THE INCREDIBLE HULK. The tone could be like the Arkham games, comic book but dark. The source could be THE LONG HALLOWEEN, or something like that, with multiple villains, kind of like the Flash. There could also be references to Metropolis or Oliver Queen.
2018: JUSTICE LEAGUE: This could be were Darkseid attacks the planet, and Superman must work with Batman, Wonder Woman, Flash, and Green Lantern to save the world. The tone could be like the 2009 STAR TREK. At the end, the JL is formed, and there are references to Aquaman, Green Arrow, the Atom, etc.
Phase 2 could include sequels, along with AQUAMAN, GREEN ARROW, and HAWKMAN films. Be sure to let me know what you think in the comments and remember, it's my first article.