All useful groups follow a pantheon model.
The obvious here are Morrison's early JLA, and the Authority under Ellis, before brainless hacks decided to ruin it. Seven-member groups. I know that the average gaming group is less than eight people, but I'll come to that later.
A pantheon works on archetypes. Each archetype is flexible but recognisable -- splats, in all but name. The archetypes are bold and brash: Leader, Sun, Champion, Death, Maker, Messenger, and World/Realm. To go back to the briefly named comics, the breakdown for each is as follows.
Each has obvious and inobvious tropes, hooks and other things to hang the character off. Each also has superlative traits that, completely aside of super powers, work to reinforce the archetype. Unknown Armies had the Avatar Channel concept that was similar. But I digress.
Characters pick a Major and a Minor archetype. The Major gives them access to all Schticks of that Archetype. The Minor gives access to one set of Schticks for that Archetype. Major and Minor is the same? All your Schticks must be of your archetype, but you get a significant discount.
Archetype Schticks are divided into power levels and so on, with multiple Schticks per level. Minor Archetypes get access to one Schtick per level in a themed progression chosen at chargen.
I could probably go into a lot more, clean it up and make it make sense, but I'm too tired at the moment.