What do you consider to be the "fundamentals" of a good network management that one should strive to get right before moving onto more advanced things?

Looking for a list of BCP or just rules of thumb for Network management that one should have ironed out before considering moving onto more advanced things.

I'll start with:

• Authentication: You should be using AAA on all devices, it should consistent, with a well documented "fallback" or "lastresort" password on the devices.

• Login protocol: All devices should be using SSH only at this point, Telnet should be disabled

Anyone have more, I can edit/add them to the OP.