An emergency kit is basically a collection of all the supplies you will be needing when an event of a disaster strikes. When it comes to your emergency kit preparation, organize your supplies to the most important up to the least important supplies. One might be asking on how to know if the supply belongs under the category of the most important or the less important. Ask yourself the following questions:
These questions are probably considered as the essential things that may pop in your minds. Once the questions were answered, list the things that had answered at least 2 out 4 questions provided. Do assemble and equip your emergency kit even before the "Big One" strikes. Because once it strikes, you might not have the time to collect your essential or even shop for them.
The main rule of preparing your very own emergency kit is to place your supplies in an easy to carry backpack that you can easily store at your home or swiftly take if there is an emergency. See image above for the essential supplies you will be needing once you decide to prepare your own emergency kit. 
Consider the needs of all your family members and add supplies to your kit if there’s still space. But always remember to that being prepared means being equipped with the proper supplies you may need in the event of an emergency or disaster. 
Source: [1, 2] “Get a Survival Kit” by American Red Cross, retrieved from http://www.redcross.org/prepare/location/home-family/get-kit