When you explore trails, you're leaving the safety and structure of your home for an unpredictable and unstructured environment.  You can never eliminate the unpredictable aspect of nature, but the risk is part of the reward.  To make the most of your experience, you should be adequately prepared for what might happen.  Here are some simple rules to follow and items to bring on your trail adventure:

1. Know your route, and tell someone where you are going.  Trails can be tricky, so bring a map and compass/gps to help you navigate.  When I go out on a trail, I make a copy of the trail map section I'll be visiting and leave it on my kitchen table.   

2. Carry water.  There are no water fountains on the trails (some exceptions at trailheads) and you must not drink from streams or other natural water sources.  If you do, you put yourself at risk of ingesting pathogens.   There are numerous packs and pouches that hold water bottles or bags, and you should get one. 

3. Bring food.  You don't have to carry a big meal.  Depending on the distance you plan on traveling, even a few energy bars are good to carry.  However, there is nothing like finding yourself in a nice location, opening your bag and enjoying a delicious picnic meal.  Whatever waste you generate, pack it back up and bring it out with you.

4. Carry your cell phone.  Even if you don't have a signal, some "smart phones" have survival applications.  

5. Bring a pocket knife.   A knife is useful for building an emergency shelter, safety, and food gathering.

6. Carry a jacket.  I roll up a light rain poncho, which can double as a small shelter and keep me warm.  From elevation gains to freak storms, weather changes quickly.  Don't get caught wet.  If you have room, carry extra socks and a change of shirt. 

7. Bring a lighter and matches.  You may need to use these to light a survival fire in an emergency.  However, please heed the warnings from rangers, and use these only in approved areas or in an emergency. 

8. Bring First-aid supplies.  Specifically, bring band aids, medical tape, advil/asprin, anti-bacterial wipes and an ace bandage. 

9. Carry a flashlight.  This is great if you get caught out on the trail past dusk, and it's good for signaling if you get lost.  I like the LED flashlights, which have a bright, clean light.

Also, I usually wear a hat and sunglasses and carry a small tube of sun block. 

Being prepared will enhance your enjoyment and minimize, but not eliminate risks. However, with the proper preparation, you will have a great time on the trail.