Standard instrument cables use the braided "shield" as the signal ground. Winding them up and unwinding them will make this shield become loose and the cable will become microphonic. You can hear it if the cable is on a hard surface like a stage and you shake it. When they get like that throw them in the garbage because they are unfixable.
The little tidbit about about feeling connectors to see if they're hot sounds funny but might save you a lot of money in certain situations. I've repaired many 100w Marshall heads and some types are prone to melt down at the impedance selector. On the early Marshall's the selector is a small dongle that you plug in. It's just a piece of metal bent into a U shape and moulded into a plastic handle. These little plugs can get loose and form a high resistance connection that stresses the output transformer, kills your tone and gets HOT, real hot. I've seen them melt.
So that's a small bit of reality into a mostly humourous discussion on cables. I've tried a lot of them from $10 to $200 each and have come away with very little in the way of knowledge. What I can say for sure is that coiled cables kill high end and using a huge fat cable between your bass amp and cab will improve your sound.
For recording my guitar I use a cable from Evidence audio. It has two solid conductors for signal and a braided shield for noise. It is only for recording because it won't lay flat and likely has a short life because of the solid conductors. John Mayer and David Gilmour are endorsers but they can afford to replace them while gigging.