this is what i bring:
spare walking socks
spare boxers
spare c95 trousers (which ive never had to use yet)
spare green tshirt
waterproof jacket
basic shaving/wash kit - bic razor, babywipes, mini toothbrush+mini toothpaste
5 tent pegs, 5 bungees, 2 basha poles
polish kit
softy + compression sack, no other warm kit, and def not the issued stuff
fingerless rowing gloves
jungly hat
medi-kit - useful tabs and plasters, i usually find that i end up giving these away to my section
a few plastic bags - extremely useful for when you sleep with boots on, one foot in a bag and you can slip into the sleeping bag much easier and keeps your sack clean also, except you look like a right tube when gettin out of bed so be discreet! haha. bags also useful if you need to take rubbish on the move.
peanut M&Ms and moralibo (haribo) - plenty of, esp if you have a section of guys and gals to look after
jetboil
lighter
green string
cam cream
hip flask of preferred beverage - i take port, everyone likes port, even girls and usually avoids ridiculous arguments between all the jocks about which is the best whisky/whiskey - pah!
spoon - no fork/knife required, though a fellow para friend of mine doesnt even carry a spoon, you can easily squeeze the food out of a boil in bag and if you have to stir something, then use the bit of the boil in bag you tore of to open in - give it a twist and it works just as well.
and you dont really need c95 shirt or issued belt, can be none too comfy when youve got your belt kit on.
lifeventure flask - fits perfect into ammo pouch, keeps tea uber warm.
red head light, a basic maglite is shite cos you cant use 2 hands unless you wanna slabber all over the light by holding it in your mouth.
multi-tool - i recomend leatherman or a gerber, keep this to hand at all times
duct tape/gaffa tape/insulating tape (green/black)
also something to do if you can get away with it, when norgies of tea are brought round and left somewhere near to you in the harbour say, save yourself the hassle of firing up your burner and put your boil in the bag in these norgies of tea. they float and will become much more thoroughly hot than they would in a mess tin/jetboil.
oh - youll notice that the biggest piece of extra kit i take will just be my softy which is in itself very small when compressed. also, get 2 extra buckle clip pouches for your webbing - one for sweeties, the other for the jetboil (or alternative gas stove).
and thats about it, though im sure ive forgotten to include something.