SPARES ahh yes.
i always have in my bag,
Spare....
strings
lead
battery
and the the biggy,,,,,,,,, FUSES for plug and amp
oh my fave,,, you buy cheap, you buy twice.......( only about 90% right)
and my best advice to all.... Buy and use a circuit breaker best £8 you can spend.
you gear might be good but the wiring in some venues is HORRENDOUS.
Like this one.....
http://www.ebay.co.uk/itm/RCD-Power-Circuit-Breaker-Socket-Plug-Safety-Switch-/140334475536?pt=UK_DIY_Material_Electrical_Fittings_MJ&hash=item20ac962910