I was just about to start a new thread, when I found this one (I love search).
Some of the things I have been doing with my headphones:
Cleaning pleather: Seabreeze and other skin cleaners work pretty good, don't leave a residue (and if they do, stop using them) and I think help the material last longer. Alcohol works, but will dry the material out.
Cleaning the drivers: A while back, one of my pairs of KSC-35s started to develope a rattle in one ear and I though the driver was damages. So, in the interest of seeing how things work, I took them apart. Surprise: a few small hairs (so that's where my hairline is going!). When I put them back together, I found that they didn't rattle anymore. Since then, if they start to rattle, the first thing I do is take the foam off and check the driver for hair. If I have to take the shell off I go ahead and clean the driver with a q-tip and some alcohol.
Foamies: I've worn out three sets of foam covers on KSC-35s. A bargain source for replacements is a pair of Koss cheapies from Wallyworld or similar stores. Last summer I picked up 3 pairs of $5 phones to use with a DVD player on a road trip and each came with spare foams. Happy kids, happy dad.
Cords: I did a cat5 replacement on the 35s a few months ago and use a braided nylon cable cover and heat shrink. I've found that this type of jacket goes a long way to preventing the wires from getting tangled, kinked and knotted. Tried it on my unaltered pair and noticed the same.
Connector: A Caig ProGold pen is great for cleaning the tip and I think benefits the jack you plug it into.
Anybody else have any tips to share?
(still haunting the dark corners of head-fi)