So two of the main things that are going to keep any of us alive out there in a SHTF scenario are going to be water and fire, then obviously food.
Fire I've written about a few times before and there are numerous ways to get your fire starting to a point where it will be top notch when you need this skill. Apart from making feather sticks and ensuring that you have sufficient kindling at hand, if you are in a place without dry grass and there is only wet kindling, this is a super easy recipe for a good fire assuming you have ferro rod, matches or a lighter on hand.
If you need kindling, make sure to include a sharp pencil sharpener in your bug out bag. May sound silly but finding sticks and branches that are the right diameter to use will be easy enough as long as there are trees around you. Use the pencil sharpener to create filings and then start your fire.
Another great tip which I only found recently is to make straw packets of cottonwool and vaseline (petroleum jelly) which act as great fire lighters for at least 5 minutes.
To make them, get thick plastic straws and cut them to a feasible length that you can shove cotton wool into. Take your cotton wool and lather it up with vaseline making sure that it is entirely saturated with the stuff. Push the vaseline cottonwool into the straw and then using pliers, burn both ends closed with a lighter or other fire source. These will stay waterproof and airproof as long as they are kept in a container where they don't get damaged (a tin would work well). When you are ready to use one, snip off the burnt edge exposing the cottonwool and light it with a match or ferro rod, then add your fuel to it as you would normally to get a fire burning.
As for water, it's easy enough to look for a source and having a good general knowledge of where the rivers are but more importantly where the source is. Water that has already reached the rivers is going to be tainted with all sorts of bacteria which could potentially end you. Apart from using the water filtration and purification options that I outlined previously, you should try to find water that is either coming from a fresh water spring or from as high up as you can. Mountain water (while it still has the opportunity to have bacteria in it as it is coming into contact with all sorts of substrates as it runs downhill) will be substantially cleaner than water further down. It's still recommended to boil it for at least 10 minutes or use the distillation method to get it mostly germ free.
The other option that people often get wrong is that snow is a good source of clean water. As I mentioned earlier, anything that comes into contact with substrate is going to be infected with bacteria and possibly other nasties along the way. This is one reason that you never eat yellow snow. Well it goes without saying that if there are animals around (like snow on a lawn where a dog lives), there's a good chance that you'll be ingesting bacteria from a dog's behind as well. This goes for birds, squirrels, foxes, cats anything really as well as the soil itself which is teeming with life, but generally not the kind you want in your digestive tract. Bacteria and viruses are not killed by being frozen, they simply go dormant. As soon as they are in the warm, wet comfiness of your insides, they will start to multiply and could lead to septic shock.
The other reason you don't want to eat snow directly is that something of such a low temperature is going to lower your core temperature way below the level that it should be naturally which can send you into hypothermia.
So while snow can be useful in a SHTF situation and a good source of water, it should be heated first so that it melts and optimally boiled so that it kills off the bacteria load.
Have you used any of these techniques before? What was your experience? Let me know in the comments.
Both images are mine