I Step One I
Think first of what you want your faction to truly be on, this being anything you want, now once you've thought of this thoroughly and decided what you want in your head, move onto the next step.
I Step Two I
Think of an interesting backstory on what your faction is going to be based on, perhaps it could be like mine, where I got a Japanese mafia/gang and further expanded it into an American group, or maybe if you're doing a totally new faction, then think of your own interesting backstory that kicked it all off, for example it could've been you and a bunch of youths gathering together, eventually giving yourself a name, then develop it from there.
I Step Three I
Constantly update your faction post with new interesting things, to make players further support you, and find more interest in what you're doing, for example with my faction we are making character biographies for everyone that joins, so that people can learn more about certain members and if they ever wanted to let's say join the faction overtime, they could develop on certain people, and get true vibes of what it feels like to be in the group.
I Step Four I
Include images, and format all of it properly to make it look well illustrated, and one of the KEY tips that I would heavy suggest, and that Mistah Len himself has said in the Discord, and that is to not include OOC information inside of your faction post, I can only assume people know that by joining a faction they're already giving you every perm required to do things such as CK them or maybe even torture them.
And those are what I found key to making the perfect faction, please leave a comment with what you think could further improve this thread!