People love to come and play together!
-So, the idea of creating a tab where players can submit Competitions they want to be held, and the date, and then players can sign up for them.
It could be called something like “Online Competitions”. Since a tab was created just for The League, this one too, should be reasonable.
Another good reason for this is that this becomes much more organized, instead of making Forum Posts here and there; or Facebook posts - which neither everyone sees anyway. Not everyone checks the Forum, the same goes for Facebook. Both could still be used in the future, but now everything is placed in just one place, and, best of all would be that Anyone who wants to, can just Host an event.
(Realized that it might not fit, so I just put a C there.)
After the making of it, others would see how many signups there are there. And then simply go on from there!