Invest in waterproof, tear-proof trail maps. Tyvek and plastic are significantly more durable than paper. If you do carry a paper map, fold it to highlight your area and place it inside a waterproof map case or a heavy-duty resealable freezer bag.
Always use a broad-spectrum sunscreen that protects against both sunburn-inducing UVA and skin-damaging UVB. Be aware that SPF only refers to UVA protection; read the label carefully to ensure UVB protection as well.
Carry stormproof matches and your fire-starting tinder in separate watertight containers; old pill bottles work well for this.
Carry emergency food that isn’t your favorite, most delicious thing to eat—or it may not be there in a time of actual emergency.