It is essential that you bring extra clothing.
Layering your clothes, if you can, works great.
Keep in mind that cotton is the worst thing that you can wear during the colder months.
If cotton gets wet it draws heat from your body.
If you are wearing cotton, and it gets wet, take it off immediately and put something dry on.
It is better to wear wool or synthetic fleece.
Extra socks are great for warmth.
Since an enormous amount of heat escapes from the top of our heads, it is wise to wear a cap, or better yet a stocking camp.
Make sure you have rain gear in your backpack regardless of the weather forecast.
It is very important to drink plenty of water while you are out hiking.
You should be drinking at least 2 liters of water per day.
You can either carry water in your backpack or bring a water filter or water tablets that purify the water for you do drink.
Small water filters are available that are very easy to carry along in your backpack.
Due to the weight of water I would recommend the water filter or the tablets.
Always bring some extra food.
You never know, you may be spending more time out there than you had planned to.
Some Protein bars are great and can be carried easily in your pack.
Just remember to save them for an emergency situation.
Don't forget to pack some waterproof matches as well as some kindling or other means to start your fire.
There are very lightweight, compact stoves that fit well in backpacks if you don't plan on building a fire.
Plan your hiking or camping trip very carefully.
Plan each meal.
Always be prepared for the worst.
Never leave without a compass and a map.
Bring a whistle.
You need to bring a flashlight, or a camping lantern, but just make sure bring extra batteries or fuel.
Don't forget about sunscreen, add it to your emergency kit.
It is your duty to clean up when you are leaving your campsite.
Bring a bag for trash.
Remember that whatever you bring in must also come out with you.
Leave your campsite clean for the next campers.