- Spend some time ensuring you actually want to do something before doing it. Some people, myself especially, can have the spark of GMing passion only to find it dying a few days later. If you're going to make something, commit - if you want to go for the long haul, make sure that you personally are going to put in the effort.
 - Remember that a game can live or die on your own initiative, and that should things slow down, you are obliged to get them back up. Many failed roleplays due to apathy could have been solved with GM pokes.
 - Do not be afraid to reject something because it fails to fit into your roleplay's vision. Too many games falter because the GM did not have the strength to say 'no'. Conversely, when making judgements, be sure you are able to explain them clearly to avoid a reverse 'gotchya!' for bad decision making.
 - Know your players. I'm not saying stalk the people who joined and their former posts, but on the other hand, stalk the people who join and their former posts so you have a gist of what you're working with and know how to handle them.
 - I don't think I need to tell you about using too dark colors on a dark background regularly and the stupid tiny-text format if you just carry on with the presentation you've been using. It's pretty good. Keep doing.
 - Redirect OOC troubles to your DM box when appropriate.  Shutting people down when they have a problem without followup is a good way to damage your GM rep, but having a shitshow in the OOC isn't too great either. If it's something all people should know, of course give replies to the OOC - just don't be too bogged down. If, of course, the person is unreasonable, have no trouble with bringing  it up to mods.
 - Sometimes things will fail. Go in with that as a distinct possibility however confident you are and have contingencies for yourself and your plot should that happen. Use what fails as inspiration to do something better, get new people, reboot, whatever you need to do.
 - Express your setting and wishes clearly, but concisely. Attempt to find the balance between providing everything people want to know and could know, and ensuring people can do it without having their eyes bleed. Be clear in what you're striving to achieve.

Idk, general prompts make me spew random things. Maybe I wrote something good. You decide.