Certainly no expert here but there are a lot of choices and they are dependent on what you are using whether IEM, CIEM or HP. Thees include Copper, Silver plate, Litz wire/tinsel wire, gold etc.. What IEM are you using and what sound signature are you looking for, that will guide you to the cable of choice.
One thing though, I have 4 custom cables and none alter the sound very much but what they do is improve the amount of loss in the chain and can affect the impedance of your chain. I swear my Pangea 4% silver USB cable sounds better than other USB cables I've tried but many people tell me I'm nuts(not just my ex-wife). I like my aftermarket cables for the lack of tangling, the weight and over all feeling when comparing IEM cables, I have OFC copper and SPC.