Get your bug out bag together.
It doesn't have to be an elaborate piece of technical perfection to qualify as a bug out bag. At it's most basic, your BOB is going to be a bag with enough stuff in it to sustain you for a few days away from home (or longer should the situation call for it).
Considering that I can travel around the world with just what I can bring in a 24 liter daypack, it doesn't have to be huge either. And it doesn't have to be expensive. If you are just starting out or just broke enough that every month is a financial challenge, hit up the Goodwill and Freecycle for the stuff you need. At least you will have some important items packed and ready to go in the event of an emergency.
Note that you have a .00001% chance of needing your BOB for a TEOTWAWKI scenario and a 95% chance of needing your bag for an emergency overnight stay in a hotel (ie: you are called to the trauma center a few hours away because a loved one has ended up there, a friend needs a ride to the next state this very instant and you may not make it home until tomorrow, etc).
Here's what you need:
- A backpack
- A complete change of clothing
- A toiletry kit
- Important documents (passport, copies of all of your important document on a thumb drive, etc)
- A couple bottles of water
- Some non-perishable food
- Basic emergency supplies (matches, flashlight, extra batteries, paracord, fishing kit, pocket knife, water purification tabs, space blanket, etc)
- A basic first aid kit
- A spare charger for your cell phone
- Cash and a credit card with a zero balance and high limit
- Spare medication or medical devices
- You should be carrying your wallet, cell phone, sunglasses, etc
- A weapon (maybe, depends on the situation)
That's all you need for most bug out situations that you may find yourself in. You can, of course, grow your kit from here but remember that you want to blend into your surroundings (a 90 liter tactical pack, in most instances, does not blend in with your surroundings). You also want to be able to easily carry your bag for long distances (carrying a 90 liter pack for miles on end is going to make you want to kick it repeatedly after the first couple hours).
Remember, you want to be generally prepared for anything but on the other hand you will still need to carry all of this crap, possibly run with this bag on your back, protect the stuff you are carrying from others who might want to relieve you of it, and utilize as many items as possible in multiple ways. Having stuff is good but you don't want to buy every item on the shelves at REI when your ingenuity can suffice as a replacement for many of those items.
Go forth and build your bug out bag!