Basics: LABEL YOUR EQUIPMENT...

The Kandinsky is painted on both sides! -- "Six Degrees of Separation"

Don't just label your gear, label it on both the front and the back. (Or the sides/top/bottom -- whatever sides people are going to be using to identify the equipment and work on it.)

This sounds kind of obvious, but I've worked in places where this seemed to be a strange new concept.

Clear labeling of your network equipment, on both the front and the back can speed troubleshooting - particularly if you've got someone doing the hands-on work who is less familiar with the setup. If you're likely to have colo staff doing remote hands work, be even more fastidious about your labeling.

Make sure that the label is visible. If your machine has a separate faceplate that needs to be removed for maintenance access, label the faceplate and label the surface under the faceplate. That way, if someone puts the wrong faceplate back on the machine, a person doing maintenance can see the mismatch.

Make sure that the label is well-secured. If it's falling off or has lost its adhesive, replace it or tape over it with clear adhesive tape to re-secure it.