Survival skills you need. Some shelters can be built with no tools
The debris hut, also known as a leaf hut, can be built without saws and axes, All you need is the available material at hand. Make sure the spot you choose for your debris hut is plentiful in material to build. You will find that this shelter can only be used then. The lack of abundant debris will make this shelter useless in wet and cold conditions.
Survival skills and snow shelters
During cold conditions when enough snow is available the snow cave will save your life. Especially if you need shelter above timberline. On the ridge of a mountain for example. The best way to dig a snow cave is with a snow shovel. But, if you don't have a snow shovel, you can use snowshoes, tent poles, or your hands to dig.
Emergency survival shelters
For shelters to be effective, you need to have plenty of needed material on hand. As an example, lean-to shelters use large amounts of firewood to heat the whole front of the Lean too. A good rule of thumb is to estimate the amount firewood you will use, then double or triple that amount.
Shelters built-in low areas along rivers and streams will flood. Standing dead trees, stinging insects, and poisonous plants all pose a risk to the unwary. So, a good shelter in a poor location is still a poor shelter. Survival skills teach you this.
Staying alive in the wild
Most of all, staying alive in the wild is due to your ability to apply experience to the conditions at hand. A 'never give up' attitude and your ability to think clearly in your new reality will make you a survivor. Hence, survival skills and survival training can help you make it out alive.