Knowing where you are and where you are going is critical to any survial strategy. Having the necessary skills and tools to acquire these two key pieces of knowledge is a big step in the right direction.
Map & Compass
The use of a map and compass is probably the most valuable navigation skill to have, GPS is easier, but vulnerable to far too many failures modes to be relied on.
The sun may be used to establish cardinal direction.
Stars, the North Star in particular, can be used to establish both location and direction if you have adequate knowledge of the movement of stars in the sky through the year.