...I don't even know where to start on this...here's some scattered ones.

1. Mods actually have to be active.

Biggest thing to make a forum run, is starting at the top. If next to nobody is doing anything, like enforcing basic forum rules. People will realize this and take advantage of it. If the mods are gone, make more of them. Preferably people who haven't attacked or harassed other users before and are actually active users themselves.

2. If you're going to even have forum rules, actually enforce them.

Self explanatory. Ban users if they break the rules more than once, even temporary bans do more than wagging your finger at them. Don't need to be ban happy, give warnings first, but if they literally break those warnings in hours later. It gets to the point where their testing the waters. Give them that leeway, they'll get worse.

3. Have a community that does not tolerate bullshit, and help point out those who don't follow the forum rules.

If you see someone breaking the rules, unintentionally or on purpose, inform them immediately. New users will feel far better if they actually see people defending others from harassment, if everyone just rolls their eyes and goes "trollz lul." New users won't fucking bother.

4. Community Stuff (Wouldn't hurt.)

Like someone already suggested contests would make it feel more like a community and maybe get more people involved. I've been dabbling in a couple ideas myself, though not really sure if it would be worth committing. But I thought of possibly creating a forum podcast of sorts. Try to get different people on the forum on, and discuss games or different subjects, something not overly controversial. That and possible game streaming nights, where someone hosts jackbox games or something to that effect, make a discord and get people VCing, get people involved. Just stuff to make the forum more lively as a result...

Also if not reviving the chatbox, at least make it more aware for newer people that there is a discord...like have people mention that in introductions, usually a mod or bot would do something like that...

One thing I disagree with is having a karma system. Because I have a feeling as lawless as this place currently is, as someone mentioned. It would be abused to no end.

Also this isn't really site related but while I'm on a rant and suggesting things to improve the site, unfortunately this stuff is more individual based.

5. Don't become a GM, if you don't want to commit.

Ignoring variety. I've never seen a role-playing forum where the creator themselves quits before anyone else does, as often as I do on here. A single player going away mid-game, if I was a GM I'd be able to compromise with minimal problems...the RP is dead permanently, if the GM quits. I can't think of a more defeated purpose of wasted time. (don't get me wrong, non-communicative players suck too.)

5. As a GM try to have rules that actually make sense and need to be there. You probably don't need to make a rule where users go in an alphabetical order. (a made up example.) Don't have a few simple rules if you're also going to use a bunch of pointless restrictions anyway...As a GM you really should be able to handle what people throw you're way.

6. This is for everyone. Deal with pointless continuity problems in the IC, not the OOC. Previous forums I've been on for years, I've never experienced people getting in squabbles over free/single sentence style rps before.

7. Don't be an asshole. Like really, if not for your own sake or the ones your being assholes to sake. But the lurkers that browse the site and wonder if they should go here...yeah if I saw some of the stuff that's happened here before I joined, I probably wouldn't of. Because I left a toxic/bad site in search for something better, most people that look for sites like this just want to have fun, and the majority of people do not find people being assholes, assuming or interesting. ^-^' If you actually care about a site you're participating in, try to respect the rules yourself and do you're best to follow the rules you'd expect/set for others.