Otherwise, cables are so cheap, just go to PB, get some nice new cat-6 ones in the lengths you need and a pretty color, replace them and see what happens.
Certainly for your core routing gear atleast, i would push making sure to have decent cables. Nothing worse than a badly self crimped cable linking the whole network to the router! - had a friend who did this, next time i was round made a point of re-terminating it properly.. he was still just putting up on it rather than replacing it :/
Using colours on key items is also insanely helpful, colour code anything for router, modems and WAPs so you know which all your core gear is at a glance. I would also highly recommend a colour for any POE gear so that you dont mistakenly stick it into places it should not go..