Through the years, I've gotten more experienced with MediaWiki, and one thing I don't think is known all too well are the Special pages.
Special pages give useful information about what's needed, what isn't updated, what's linked to the most, what's linked to the least, what has or needs no information, what has the most information, what nobody cares about, what everyone cares about, what used to be, what forces you to click the home button, what hurts the servers, what has Valve Anti-Cheat, what gets organized the most, and what files people like to look at/use.
Special pages can especially help for figuring out what needs work, etc. and you can also get some interesting data to draw conclusions from.
I thought this would be usefuuuul.