You can divide the skills necessary for wilderness survival into 7 categories. I have not listed them in any special order, except #1 which is essential for survival.
You should use the 6 other skills in the order relative to the situation you are in.
1. Positive mental attitude
2. First Aid
3. How to construct a shelter
4. How to make fire
5. How to get water
6. Navigation & signalling
7. How to get food
To be able to use the different skills in the right order, could be a skill of its own. It is important that you have received some kind of survival or wilderness skills training, and have had the opportunity to use the skills in a demanding environment, so you can be able to judge how to deal with a survival situation.
You can read more about the different skills on my blog – or even better – join my courses and try them out in a controlled environment.