Equipment: snowshoes and mountain poles with baskets at the bottom.
Clothing and accessories: Bring appropriate winter clothing, thick socks, waterproof footwear, a hat, gloves, sunglasses and/or storm goggles, and gaiters to prevent snow from getting between your trousers and boots. Hand and/or foot warmers are also a good idea in case you get too cold. Bringing spare gloves or socks is also a good idea.
Food: Bring water and snacks, as well as energy bars or nuts. It's also a good idea to bring a thermos of broth or some hot tea.
Safety: Bring a fully charged mobile phone and a spare battery. If possible, bring a GPS device. It's also important to bring a thermal blanket and a first-aid kit, as well as sunscreen for your face and lips. On more demanding routes, basic avalanche safety equipment (avalanche transceiver, shovel, and probe) is necessary.
Other items: It's a good idea to pack a blanket in your backpack in case of snow and a waterproof bag to protect items you want to keep dry. If you plan to summit any peaks, crampons are essential.