The key when it comes to deciding what to pack on a hike is to pack only what you are going to need for your comfort and safety and nothing more. It is the simplest thing in the world to find yourself packing everything including the kitchen sink, but all this is going to do is to wear you out carrying a mass of useless gear around all day. Accordingly, take the smallest backpack possible and fill it with only essentials like water, enough food for the trip, a map and compass, a basic first aid kit and a lightweight waterproof jacket. If you find yourself putting anything else into your pack then stop and ask yourself why you are packing it.