I was thinking about what I want from WB's slate of DC films. Most may not agree, but here it goes...
I want them to nail a particular tone and work around that. May it even be a dark and gritty universe. Like Marvel has. If Marvel's films are to be 'fun, popcorn entertainment', DC should look to being something more by focusing on 1) grounded, cheaper, gritty superhero action films that don't necessarily focus on massive spectacles, and 2) Event films that are nothing like Marvel's, by focusing on more larger than life events and stories from the 75 year history that are, again, not focusing on huge as fuck 40 minute climactic showdowns, but something more cerebral, like Final Crisis for instance (though having toned down version of them won't hurt as every film will be its own thing, but they really need to nail the tone of their universe down).
I also want them to look at more risky projects down the line, like Doom Patrol, The Invisibles, Y: the Last Man, Batman's R.I.P storyline and more. It doesn't have to necessarily be focused on superheroes only. It's how they can differentiate themselves from Marvel, and be their own thing. The worst they can do is pander to the big audience, order re-shoots to make things more popcorn-ized and what not. Marvel has that space and will continue to do so.
Also, and this goes without saying, they need to stop interfering in their projects and have some faith in their filmmakers that they have chosen.