i tag (with the label maker) the SSC's, and LE channels.
the SSC's I tag each one, right after it's been programmed, so i know what order it is (SSC03) and what channels it handles, incase i need to focus on that area if there's a problem. (281-400)
i usually attach my extension wires to the LE prior to taking it outside (learned that mistake last year)
i thought i'd need to label them, but opening the door as you plug stuff in helps you keep track. (plus the onboard test is the verification)
extension cords, i don't need to mark, as I only use about 4.
spt cables, and cat5 cables, i lay out bu distances, and then pick and choose what i need for where it's going.