The best thing to do during a zombie apocalyptic scenario would be to follow survival instincts, and refining them by observing possibilities you and your group may face. Plan for in the short term and for the long term; what would you need, where would you go, how in the world are you going to fix what has happened. Question everything, but be fair. Don't underestimate anything. Stockpile items you will need. All of this is something you need to remember.
A lovely example of a guide already written up is Ariel Williams' Zombie Survival Guide below.
Ariel Williams' Zombie Survival guide.
- Have a supply of emergency food that grows over time.
I buy 10-pound cans of freeze dried food from places like Mountain House and Backpackers Pantry once a month. To be honest, this is not for zombies but just for emergencies. These cans last for 25 years: Buy them once, keep them forever. If you ever get stuck in a storm or disaster, you will never need to worry about food. Buying one or two cans a month, eventually I will have enough to last me many months, needing only water to re-hydrate them.
- Keep a 12-volt battery-powered water pump. If the power goes out for long enough, so will your water and water pressure. I can turn on this pump and get enough water to fill several 50 gallon water barrels even if the water stops flowing on its own. The pipes in the house alone likely have many gallons. (Note) this is very loud when in use
- Own a sewing kit and a first aid kit with basic surgical gear and a military field medic manual. It should have butterfly sutures and a tissue stapler. Most first aid kits are filled justn with many sizes of bandages. Instead, model your kit after the ones they use for field medics in the military.
- Download and/or print all of the U.S. military field guides you can find.Most are available free on the Internet. They cover everything from food and water sources for survival to organizing a population that has been displaced. This is amazing stuff. They even cover things like military tactics and strategy and how to fortify a position.
- Water heaters are a source of many gallons of stored, clean water. Most residential water systems use chlorine in the water, which will keep that water fresh for a very long time.
- Own a baseball bat for people. Own a Two Handed Kukri Machete for zombies and for thick brush.
- If you feel you must own a gun, make it a 9mm. This is the most common caliber of weapon anywhere. Shotguns are good for convincing a crowd to stay back. Small pellets embedded in many people's skin has that effect. Shoot at the ground in front of a group of people (concrete / blacktop), and it will disperse the pellets widely even at short range. While they are hopping on one foot or fall down, get away. People can be just as dangerous as zombies in a disaster.
- Most common warehouses would be very secure in a zombie outbreak.Metal walls, doors, and no exposed windows at ground level. If the zombies did get inside, you could easily have a ladder ready to get to the ceiling trusses and skylights. Personally, I think the best would be to take over either FedEx or UPS's warehouse. It would be like a continual Christmas with all the wonderful things you might find in that place at any given moment.
(Oh look, a chainsaw, Grandmas cookies, clothes, bullets, etc.)
- Pulse monitors on everyone. These could be found at any pharmacy and are not likely to be high value looting targets unless you read this answer. A bit of work from someone with electronics experience on each one and it could be made to let out an ear piercing squeal when you die. (Wire a peizo buzzer to the warning light.)
- Zombie power station / zombie mill. Take zombies and remove their arms and lower jaw. Chain the zombies to a rotating shaft and have two people on opposite sides watching them. They will wander towards the human keeping the thing running. The torque could be used to run a small generator forever with no fuel or to run mills and such. Several of these in series could power a small city. With no arms and no jaw, they would be harmless if they escaped.
- Zombie machine. Similarly, arm-less jaw-less zombies could be used to power carts in a big zombie hamster wheel sitting behind the driver.
- Sleep on the roof. Make a tent or such. If they get in while you're asleep, you will be fine for a little while.
- Regular full-body nude searches for bite marks on anyone that has left the safe haven for any reason, for any amount of time. These will be done by at least two people, ideally three. Mandatory bite mark checks every three days for everyone else.
- If you can't find an exit, make an exit. With a large piece of metal (shower rod, pipe, part of a bed, large lamp. etc) and determination, most walls can be smashed through with time. You could even potentially smash your way up through the ceiling or down through a wooden floor.
- Zombie traps 1. Build deep ditches and have a solar or wind powered device that draws zombies in with a human sounding noise. Occasionally, burn the ditch. When it gets full, refill it with dirt, dig a new one, and start again.
- Zombie traps 2. Something as simple as strong rope can stop most zombies. Weave the rope back and forth in a zig-zag pattern as a wall across a street. The rope should be designed so a human can squeeze between the pattern, but a bunch of zombies pressing against each other will not. This is meant to slow zombies and let fighters or survivors get away.
- Zombie traps 3. Wooden stakes and kite string or wire braided across the ground back and forth will trip zombies, but humans could walk past it. This should be used in your compound to slow the flood in case of breech.
- Zombie traps 4. Metal poles could be installed in the ground at choke points with just enough room for one or two persons to slip through at a time. These could be used to trap or kill zombies by slowing them to a trickle that gets through while the horde is stuck pushing on each other.
- Motorcycle gear is great zombie's armor. Anything that can prevent road rash can stop you from being bitten. The helmet is also good. The sports stores will have dehydrated food and the motorcycle riding clothes, people might steal the food, but are not as likely to steal the riding clothes.
In absence of motorcycle gear, wear multiple layers of long sleeved clothing. Even if the zombies are abnormally strong, with three to four layers of clothing, they won't be likely to bite through. Wrap a towel or sheet around your neck. This approach might be harder in the desert, but even thin long sleeve shirts will likely stop mouth to blood contact even if you still get bruises. Also several layers of cotton might feel warmer, but will actually slow the effects of dehydration.
- Set a bite policy upfront. If you are injured and suspected of being bitten, you have three options. Everyone knows the rules. Suicide, exile, or lockup. No exceptions.
(2.) Exile. (If you are still alive a week later, we can take you back.)
(3.) Lockup. Remain locked to a bed or in a cage until you either change or the known incubation period is long since over. You may also be gagged and have your fingers taped into gloves for our protection. If you change, it's no longer you and we kill it.
- New refugees policy. They must be strip searched to the skin and have a full body inspection by two different groups of three people before being let in. New people will be required to clip their hair short enough to see any injuries, all hair! They must then stay separate from the population for the incubation period of the disease. The short hair/buzz cut will also mark them as new so people know to be a bit careful around that person until they have proved themselves. The last thing you want is sabotage or insurrection by a rival group. By the time their hair grows back, we should know if they can be trusted.
- Work to get out of the cities when it is safe. Dead bodies and rotting food will make them disease centers.
- Water. Know that you need a gallon of water per person, per day for drinking and hygiene. More in the summer. More in the desert or dry environments. If you decide to move, you need a huge supply of water to bring with you. Get a food grade tanker truck or a water delivery truck and fill it for your convoy.
- Gasoline. Most gas stations have huge underground tanks. If you are careful, you can access these without power. Make sure you have a heavy duty hand pump made for gasoline.
- If you are entering a new environment, make noise. Bang on something inside or otherwise make some noise. This will give you a clue as to how filled the building is. If you don't get a response quickly, then there may not be many walkers nearby. Creeping around quietly when exploring means you might walk face first into a hoard and be unprepared. Find a place with a good sight-line, like inside the hallway or near the exit with a view of the whole room, then make some noise. Then, you can escape if the place is infested. If it is infested, bar the doors, mark it with a big Z with a circle and leave.
- Recessed metal rolling shutters can make your house mostly burglar proof and zombie proof. When installed recessed in the walls at the time the house is made it can make it extremely secure. These are also great in hurricane prone areas to prevent damage. They can even be used to seal off areas like patios.