A crisis is separates people into two distinct groups: those that rise to the occasion and those that freak out. Oftentimes, people freak out when a crisis hits because they immediately revert to their instincts, which causes them to make bad decisions. Therefore, it is important to have a set of rules to abide by WTSHTF. Remember this: the key to a successful crisis management is calm and confidence.
Step back for a moment, take a few deep breaths, and assess the situation. This is the point where you fight every instinct to react or overreact. After you've collected yourself, do the following:
Immediately think of everyone who would be affected by the situation. Single out those who you trust and get them involved. Doing so makes your decision-making and response all the better. Moreover, when a crisis hits, people that are close to you don't want to feel like they were kept out of the loop. Involve them if possible.
If you're reading this, you're probably a prepper or survivalist; therefore, you know that WTSHTF, planning empowers you to act quickly, decisively, and effectively. Once you've gathered the facts and secured advice from trusted people, come up with a list of best, typical, and worst case scenarios of the situation. Then develop plans for each one. In other words, if x happens, then you do y.
As the saying goes, be proactive, not reactive. Obviously this is harder than it seems in the event of a crisis, because telling the difference between the two is not easy. Follow the above steps of ASSESS, ENGAGE & PLAN. By doing so, you'll know when and how to take action -- that is, executing.
In order to execute, you must grasp the reality of the situation and act on it. Don't view your response to the crisis as putting out fires; instead, your response should be the execution of your plan (#3). Get your facts and data, organize your priorities, and go.