Our standard list for two nights in the hills, from the people who test the gear: tent, sleeping bag and mat, stove with a small canister, pot and spoon, a headlamp with spare batteries or a full charge, a warm layer, a rain jacket, and one more pair of socks than you think you need.
Food: 600 g of dry food per person per day is plenty. Water: carry one litre and treat the rest. Leave the cotton at home, it never dries.