I've got a mate that goes off at me for all the spares that I carry and have never used. He however has had to use the following of mine, clutch cable, WD40, cable ties, insulation tape, fuel hose. I am still on my original 25 year old clutch cable, which against advice I lube with a PTFE lube called Tri Flow. It will not effect the Teflon cable liner as some lubricants can do, it's available from bicycle shops.
Regards Martin.