Here are the crappy ones I made when .flaS was still playing.
Lockdown:
Lostvillage:
You really dont need to be that specific as far as callouts because even in the leagues that are now non-existent, players move so fast, by the time you call them out they'll be somewhere else. We used to say things like "crate house lower, going hidden xbow" that sort of thing.
And look at mine, I made mine in less than 10 minutes total for both. They don't have to be super fancy, just use what works.
There is also a program that is supposed to generate map overviews called Gtactix or something. Google search it. And be sure to let me know if its legit. lol
Also if you plan to make your own, use that overview guide that The Dog posted. I had no idea there was such a guide and a way to do that until now, so dont make the mistake of doing what i did. Also, if you plan to make your own for your own team, keep callouts as simple as possible. The shorter your words, the better off you are. Keep things from sounding like other areas.