Size and capacity: Choose a backpack that's the right size for your needs and has enough capacity to carry all your gear. Material: Look for a backpack made from durable, water-resistant material that can withstand the elements. Comfort: A good backpack should have padded shoulder straps, a hip belt, and a back panel that provide comfort and support during long hikes. Organization: Multiple pockets and compartments help you organize your gear and make it easy to access everything you need. Laptop sleeve: If you plan to carry a laptop, look for a backpack with a padded laptop sleeve to protect your computer. Hydration system compatibility: Some backpacks have built-in hydration systems or are compatible with hydration reservoirs. External attachment points: Look for backpacks with external attachment points for carrying gear like trekking poles, ice axes, or sleeping bags. Compression straps: These help to secure your load and prevent it from shifting around inside the backpack. Ventilation: Mesh back panels or other ventilation systems can help prevent excessive sweating and keep you cool and dry during hot weather. Style: Choose a backpack that suits your personal style and preferences. Backpacks come in a variety of colors and designs to match your taste.