This is not a "How to" article, I am apologizing ahead of time in case it does come off as one and I don't want the Justice League film to be like The Avengers. It needs to be different but in a strong way. Some of my choices may not be the greatest but, I think they are solid choices. Lets start off with the roster. The roster can't be too crowded but it also needs to be one that makes sense for the story. Who I think should be the roster is: Superman, Batman, Wonder Woman, The Flash and Green Lantern. That's it. No Aquaman, No Martian Manhunter (although Martian Manhunter would be cool, he just doesn't fit into the idea of the debut film). I have no casting ideas or anything. But, I believe this is the roster they should go with.
Director(s)
This is going to be a hit or miss choice among you considering you guys want to see someone like Zack Snyder directing. I prefer a director(s) who are experienced with action movies but not so much with the superhero/comicbook genre. My choice is The Hughes Brothers.
They're not the greatest of directors and I'm not a big fan of their work but, anyone who has seen The Book of Eli knows that these directors can nail a gritty and dark action flick. While, I'm no fan of the movie, I do think it would be interesting to see a Justice League movie with these guys at the helm. Especially considering that's the tone that Warner Bros. wants for their Justice League film.
Villain
Yes, I'd like to see Lobo be the villain in the debut Justice League film. Don't make him a wise cracking sort of humorous villain. Give him enough of an upgrade so he is a vicious, brutal villain. This is someone that needs to feel different and be different from Loki in The Avengers. Sure, Lobo can be someone that Superman can take on his own but, I think he provides a challenge due to his abilities that makes him a worthy villain for the League. My idea is to have him be a Bounty Hunter (this is going to be similar to The Avengers) and be hired by a mystery figure who wants to rule earth. The heroes of earth defeat Lobo and Lobo decides to make it personal and wants to take out the Justice League himself. We never see in the movie who this mystery figure is.
Stand Alone Story
Okay, this is another one that's going to be similiar to The Avengers. The Amazing Spider-Man made a mistake of making it feel like a lead up to a sequel rather than be a strong stand alone movie. The Avengers was a VERY strong, stand alone movie that can't feel like a lead up to a sequel. But, while we are on the topic of a sequel. The idea I have for should they ever make a sequel to Justice League is adapt the story "Identity Crisis" When you look at the story, it seems like a great direction to go with for a sequel should one ever come out.
Zack Snyder shouldn't be completely out of the picture
He shouldn't be out of the picture with the exception of a Man of Steel trilogy or whatever direction they chose to go with their films. While I find him to be a hit or miss, he does make good comicbook movies and knows what he is doing when it comes to those movies. He should be Warner Bros. Whedon and help over see the DC Universe.
I'm sure most of these ideas have already been shared but, I wouldn't know. Comment below and be respectful.