Standard Aircrew Pocket-Fillers
Here's my semi-serious take on this.
The RAF carry in their pockets:
Lower leg - chip hat (specially designed for the crabs so that when they landed away they could walk to the Officer's Mess with headgear. Other Services could substitute a Beret. I used to put Maps/FLIPs in there when flying FW but now they stay empty in helis where I have a handbag full of them, and maps. Also useful for gloves when on the ground.
Knife-cutter pocket - Knife, useful for cutting straight lines quickly in maps (blunts the blade a bit so I'm told)
Kneeboard pockets - what do you want to write there? There's plenty of space for frequencies, plan of 2 airfields, spaces to write QFE etc. You could get a kneeboard attachment with a foldery thing in to keep even more useless info in. Obviously if you have bad eyesight you'll need to write bigger, so you'll fit less in (but maybe if your eyesight's that bad then you shouldn't be flying!).
In the large velcro knee pockets that open away from you when sitting I kept FRCs (when they were small enough to fit in there). Ones that face you are good for stuff you don't need in flight such as directions to the nearest hotel/pub at destination/half-filled out JPA audit sheets.
Chest pockets are good for wallet, mobile phone and other stuff that you don't need, assuming that you are wearing a parachute or life-jacket, as all mil people are.
Pen pockets on sleeve good for pens, AA maglite etc. Have to be careful about loose article hazard in your sporty little a/c though.
Hope this helps in some way(!)
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P.S The RN carry extra-large condoms, breath mints, musk, drag fancy-dress and cash. Also some waterproofed sweets for recharging your batteries after a long trip!
P.P.S Haven't got a clue what the army carry, probably a camo net, hexi stove and a big knife. Not forgetting gun-dog (Officers), football boots, ball and shirt (NCOs).