Navigation devices: You cannot rely solely on cellphones in the outdoors; especially not if you're lost in the woods. Using apps with GPS navigation is super helpful, but it is important that you always have a backup plan in case your phone dies or breaks at any point in time.
Eat the right amount of calories, especially enough calories to burn off. Consume double the amount you normally would. Weight and space consumption: Choose lightweight items to carry. Repacking in a resealable baggy. Dehydrated meals.