1. Water - lots and lots. A 1 per cent drop in hydration equals a 10 per cent drop in concentration. Someone told me that once.
2. A nearby toilet (see item 1.)
3. Savoury snacks - wasabi peas, sunflower seeds, toast, a plate of cold meats, or preferably all of these together on a tray.
4. Sweet snacks - chocolate covered sunflower seeds, chocolate, mentos, etc.
5. Lip balm - because I seem to lick my lips a lot when I'm thinking, and my lips get dry.
6. Eye-wash - because I keep getting lip balm in my eyes (don't ask).
7. Music - must be instrumental so I don't start singing along. Usually crazy jazz to stimulate my brain.
8. Dictionary of Classical Mythology - wonderful source of names, stories and general inspiration.
9. Glass aubergine - an ornament into which I can stare for hours on end, in deep contemplation.
10. Motivational signs - I have a few of these. They read:
"I don't get stuck, I get hungry." - as in, "Don't waste time sitting there if you're not being productive. You're only being slow cos you need a snack-boost. Get something to eat and come back."
"Er, hello?" - as in, "Er, hello, what are you doing? Shouldn't you be working?"
"Pascal." - I can't remember what this one means, but it seems to work.