Here is a kit reminder:
Hillwalking boots and socks
Leg wear (not cotton)
Several tops / thermal layer (not cotton)
Waterproof jacket, waterproof trousers and gaiters
Rucksack
Hat, glove and spares
Spare clothing / extra fleece (based on what is needed plus one spare)
Map, compass and whistle (and GPS if you have one)
Head torch and spare battery
First aid kit / medication
Personal bivy bag / shelter
Sun block, sun hat and sunglasses (especially in snow conditions)
Food and drink (and spare food)
Midge repellent and net (and tick remover in summer)
Ice axe and crampons (in winter)
Ski goggles (in winter)
Mobile phone / money / keys!