1. Don't tell someone where you're going
If you've seen the movie 127 hours, you know that this is never a good idea. No matter what your relationship with family and friends, always tell someone you trust where you're going, for how long and when you expect to be back.
2. Don't bring extra food, water and layers
A lot of hikers hesitate to bring extra clothing, food and water because of the extra weight. Many reason that they will only be gone a few hours, so why bother? I have also been guilty of doing this myself, preferring to go pack less on trails I know well. However, anyone who's been lost will tell you that you'll appreciate these extras in an emergency. A thin down jacket and toque pack down so small, are so light but super warm. It's hard to find an excuse not to bring them! Don't want to bring a backpack? Fanny packs are a styling alternative!
3. Don't bring and emergency shelter or blanket.
If you get lost on a hike, something that can happen more quickly than you would expect, you will be so glad you threw one of these in your pack!! Very lightweight, they keep you warm and boost your morale, which helps you make better decisions if you have to hunker down somewhere for the night.
4. Leave the trail.
Don't do it, for any reason, even to take a shortcut. This is the main reason people get lost in the wilderness. In the mountains, be extra careful about staying on trail because every dip and animal run looks like it might lead somewhere.
5. Leave your cell behind.
Surprisingly, hikers sometimes leave their phones at home or in the car at the trail head. Some assume they won't get coverage, others hike to get away from 'it all', so why bring a phone? While I can understand the reasoning for both, I always bring my cell phone just in case. Cell coverage extends farther than we think. On several occasions I've been able to call home from a mountaintop! Turn it off if you don't want it ringing on the trail (which has also happened to me, pretty embarrassing) but DO bring it! If you get lost, it can help search and rescue pinpoint your exact location, making your rescue much faster.