And no, I'm not talking about using the rhythm method while wearing a rubber when your girlfriend is on the Pill.
What I mean is using three levels to prepare yourself in every category. These would be a short-term, long-term and (for lack of a better term) a middle level of preps. Dividing up your thinking allows you to split a problem into something more manageable. It also allows you to tackle many categories for the short term without getting yourself lost trying to go whole hog at once.
Let's face it, it can be so easy to go nuts and max out the credit cards buying the latest Gen III nightvision scope for the customized battle rife with the 300 magazines and 4 billion rounds of ammo you bought. The four pallets of MRE's are on the way with the five water purification systems and gas masks, etc. were bought with the home equity loan you were going to use to fix the roof... I can't do that, I haven't won the lottery yet. Prepping can be done on the cheap. It's remarkable how little cash it can take, if you spend your prepping dollar wisely and you follow a plan.
Take food for example. My short term solution is what I have in my freezer, and in the cupboards of my house. The moderate level would be all my canned goods and grain I have stored. The long term solution to food would be learning hunting and animal husbandry skills and growing vegetables from open pollinated seed.
For water, I have bottles in my fridge, freezer, and pantry with a few drops of bleach in them to keep them good. That takes care of the short term. For moderate term I need to start catching rainwater and use my Katadyn filter. Longest term is to filter it through coffee filters and boil it. It's not the best solution for now, but it should be quite serviceable. This allows me to focus on the other areas that need prepping. The amount of time, effort, or resources to improve the water situation, would have a lot more effect if applied to another area.
Every segment of prepping can be broken down this way. Medicine, firearms, security - the list goes on. Also by thinking in these phases, you consume your preps along those lines. Your short term supply is generally has the shortest expiration of all your preps, so it is what is rotated out the fastest, and is most likely stuff you use on a (somewhat) daily basis. So that bag of chips on the counter wasn't purchased as part of my preps, but when a snowstorm buries the house, it just got drafted into the preps.
Another way of looking at preps is from most likely to least likely to be used. Medical and security preps seem to "fit" better to this path of thinking. Band-Aids are the most used with disinfectants while child birthing kits are a lower probability of use. Or, I should say, less frequency of use. Unless your Irish Catholic, then you better have plenty (just kiddin')!
To my mind you would more likely need a kevlar vest, than a pile of biohazard suits and dosimeters. But then again I'm not trying to prep for WWIII, I see the biggest threat from social unrest and economic collapse. If Iran ever gets a nuke and ICBMs I would need to re-evaluate.
If you have not started to prep it is not too late. Please go out and try to get others to start to do something, anything to get ready for hard economic times. Even if you have only a weeks worth of food and water saved when the poop his the fan, the you are a week ahead of everyone else. You have a week's worth of buffer between food in you families belly and starvation.