Actually, I think Bear Grylls' covered this topic pretty well in his book "Living Wild" and I would basically echo his thoughts on this matter (you can check it out online here - p.249). The wisest thing he does, in my opinion, is to not try and come up with generic practises or methods or even speak to how faith & spirituality is helpful in a generic sense, but rather simply writes about what his faith means to him and how it helps him.

This is a realistic approach. I cannot say what will help someone with a different worldview or belief system as me, but I can relate how my worldview and spirituality helps me.

Back to what does write about, in part, he says:

My Christian faith makes me stronger and it makes me smile.It is the secret power in my life. People ask me whether faith is a crutch. Well, what does a crutch do? It helps us stand. So in some ways I guess, yes it is a crutch, but it is more than that to me. It's like a crutch that runs straight through my core. More like a backbone.

I echo this.

To the question, what specific techniques would I recommend? Coming from a Christian perspective, the most important is having a faith that is real and apart of your day-to-day life, something that is a complete worldview and way of life.

Think of it like physical training; if I want a strong body when I face a survival situation, I'm not going to wait & do push ups when I'm out in the thick of an emergency. In the same way, if I expect to have a strong faith to help me through tough times, I need to exercise it daily. For me, this means (in part at least) knowing my beliefs (not just what they are, but why), regularly being immersed in the life of the church, and serving others. So when the tough times come (and they do come!) I have a solid worldview that allows me to calmly deal with the situation.

So, like a fit person facing an unexpected long hike to get back to safety, the person who has a strong faith before an emergency arises already has the spiritual tools required to handle the situation.