Lastly, there are no “EXPERT” preppers that I know of! Just as there should be no one directing, suggesting or quantifying anyone’s efforts toward being ultimately prepared. We are all in different stages with any of the attributes required to be our best, not someone else’s best. There are just way to many factors that have to go into the equation for one person to know it all. I learned a long time ago to never point out a problem without recommending a solution. I feel survival training through this venue is best served by not casting doubt, mistrust and pointing out scary gaps in plans being worked on. Instead, Train skills, knowledge and attitudes. The “How Tos”, “Where to Find Useful Info” and just the considerations of the attitudes. Let the individual prepper decide how it fits into their specific plan.
The survivalist hard-on (yep, and I'll do it again, too) for prophylactics untouched by chemical pleasure-enhancers is the result of drilling deep (told you) into the magical properties of our latex friends. According to our research, these flexible, durable, waterproof wonders will be as much of a deciding factor in your dystopian longevity as fire and can openers.
The LifeStraw filter meets EPA standards and has been shown to remove more than 99.9% of waterborne parasites and bacteria. Humanitarian relief workers in all corners of the globe use the LifeStraw to help bring safe water to threatened communities and refugee camps. The “straw” itself weighs a scant 0.1 pounds and measures 9” in length and 1” in diameter. Few things are worse than being lost and being besieged by waterborne illness. Bring this essential piece of survival gear with you whenever you venture into the wild and make sure water problems are not on the menu.
Bombs rain from the skies, alien ships descend with lasers ablaze, improbably proportioned, irradiated sea monsters tear through essential infrastructure. You'd think that running, screaming, and finding clean underwear would top the list of activities likely to improve your chances of living, followed closely by finding a sustainable food source and offering sexual favors to the person with the most impressive arsenal. Unless you were a prepper, in which case you'd be worrying more about the safety of your cigarette stockpile.
This group stresses being able to stay alive for indefinite periods in life-threatening wilderness scenarios, including plane crashes, shipwrecks, and being lost in the woods. Concerns are: thirst, hunger, climate, terrain, health, stress, and fear. The rule of 3 is often emphasized as common practice for wilderness survival. The rule states that a human can survive: 3 minutes without air, 3 hours without shelter, 3 days without water, 3 weeks without food. 
Earthquakes, tornadoes, and hurricanes can cause you to leave your home or even be trapped there. Roads could be blocked due to fallen trees, power lines, or even damaged earth from the natural disaster. Rescue crews can not be in all places at once. You may have to wait it out for quite a while before its over. You won't be able to go to the store or to the corner market.