Survival groups should be between three to five people. Any smaller and you're too exposed to danger. If you have only one person watching your back, and they die, then you're alone, which is the worst position to be in. Any larger and you get too comfortable. People make stupid mistakes when they feel safe. Larger groups are also less maneuverable, and require a lot more coordination. If there are six or more people in a group, it's time to splinter off into groups of three to five people, when it's a safe and appropriate time to do so.
Motorcycles are perfect for a zombie apocalypse. They have exceptionally good gas mileage, have excellent acceleration, are very maneuverable, and can slip through abandoned traffic. Being on a motorcycle also makes the rider inherently more aware of their surroundings. Being on a motorcycle makes you more exposed, however. This is a good thing and a bad thing. On the negative side, this means that you are more open to being attacked. On the positive side, you are less likely to take unnecessary risks.
Avoid guns at all costs. Guns seem like a good idea because they're easy to use, they're easy to reload, and you can carry a lot of clips on you at once. The problem with guns is that they're very loud. A shot is the equivalent of a thunder clap. A silencer reduces the volume to the decibels of a rock concert. Zombies are attracted to sounds, so your hundred rounds are not enough to take care of the hundreds of zombies that you've just attracted, even if you can manage to have a 100% kill rate with every single bullet. Furthermore, once a bullet has been discharged, it's useless. Spears, blades, arrows, bolts, and traps are are reusable, and don't attract that much attention to you.
Charity will get you killed. Anyone who can't survive on their own will make a mistake that will get you all killed. If someone decides to do something that puts themselves and the group at risk, then they can act on their decision without your support. If they survive their decision, you can let them back in only when it doesn't put the group at risk. If they make a habit of risky decisions, then they can make them on their own. Better they get themselves killed than the whole group.
A zombie is no longer a person. They may look like the person they once were, but they ceased to be once they turned. Do not hesitate to kill a zombie, because they will not hesitate to kill you.
Always scout ahead. Take the extra time to scout your next path. Take your time. You don't get more than one opportunity to do something. Make sure you know what dangers, obstacles, alternative routes, and potential safe zones there are. Furthermore, don't go further than you can scout. If you can't find the next staging area in your path, look for an alternative route. It's better to take the long way around than to risk your life on impatience.
Fortify your safe houses. This is more than boarding up the windows and doors. Set traps, dig ditches with spikes in them, reinforce the walls, create a sound buffer out of blankets, place lots of weapons at easy to access locations, and anything else that will allow you easily defend yourself. Remember that your fortifications need to be able to withstand a large number of zombies, not a few very strong ones.
Always have an exit strategy. Every plan is lost on first contact. A good plan will help you survive, but you simply can't guarantee that your plan will work. Ensuring that you have a means of escape is critical. This isn't just for situations you're going into. You need several exit plans for your safe houses, too. Survival depends on your ability to escape danger as much as it does on avoiding it.
Grow your own food. Long term survival depends on being able to draw on renewable resources. None are more important than food. If you aren't in a safe house that has the capability to farm, find or build locations nearby that you can use to grow food. Zombies aren't interested in fruits, nuts, and vegetables, so you don't have to worry about losing your crops to them. You will still need to fortify your farms, however, and make sure that the paths to them stay safe.
Stay hydrated. In a zombie apocalypse, you may not always have access to clean, fresh water, but your body can go without food longer than it can water. Furthermore, if you're dehydrated, your reaction time will slow, you won't be able to think as clearly, and you'll wear out quicker. Make sure you have ways of collecting water, and boiling and filtering it, if necessary.
Build up your endurance. While ensuring that you have a strong cardio workout is exceptionally important, you mustn't forget to build your muscles for endurance, as well. There is a seemingly endless supply of zombies in a zombie apocalypse, and they do not seem to ever stop. You need to be able climb fences, trees, buildings, etc, after running for several miles. Being able to run really fast for 400 meters and lift heavy objects isn't going to carry you very far in a zombie apocalypse. Focus on push-ups, sit-ups, pull-ups, isometric exercises, and long distance running, when it's safe to do so.
When it's practical, kill as many zombies as you can. This may seem like needless danger, but for every zombie you kill, that's one less that you have to deal with later. It's best to kill them when you have the upper hand, before they notice you. To that end, while you can, focus on stealth killings, making sure to strike only when it's safe. Once you've killed as many zombies as are practical, you are a little more free to complete the mission you set out to do.
Never underestimate a medical condition. More people died from infection in the American Civil War than from bullet wounds. Blood loss, punctures, infection, fevers, internal bleeding, choking, and broken bones will kill you as effectively as a zombie, if left untreated. Make sure that you stockpile on medical supplies as much as possible. Also make sure that everyone in the group has at least a basic understanding of first aid. It could save your life one day.
Stay dry and warm. This is more than just a creature comfort, it's a necessity for human survival. Being cold and wet will get you sick at best, and could kill you at worst. Don't think that goes just for your body. If your hands, feet, or head are wet, then it can cause severe problems, especially the feet. Make sure that you keep your feet dry, and change your socks regularly, especially if they get wet. Keep extra pairs of dry socks and boots on you at all times.
Travel as lightly as you can. It's going to be impossible to survive off what you can carry in a small backpack, but you can't have any room for things that you don't need for survival. Don't keep things for entertainment or of sentimental value. If you have things that you emotionally feel that you can't leave behind, you are much more likely to get yourself killed trying to hold onto it. Since most people are zombies, they won't care if you read their books, play their games, or use their stuff to entertain you with, so there is no point in adding weight to your pack.
Arguments will get you killed. While it's best to travel only with like minded people, you don't always have that luxury in a zombie apocalypse. There is always room for healthy debate, but everyone needs to agree in the end. If you disagree with someone, or everyone, then you or they might make a decision that'll get everyone killed. If you can't agree on a fundamental level, then it's better to go your separate ways than have that conflict come to a head at a critical moment.
Take the time to train. It may not seem like it, but there is always room for improvement. Train with the weapons that you have. Train in hand-to-hand combat. Practice field medicine techniques. Don't let important skills degrade, and always look to improve them all. The ability to kill zombies more quickly, perform field repairs, or place a tourniquet may save someone's life, or your own.
Be a good neighbor. Don't do it at the expense of your own safety, but the life you save may be the one that saves your life. It's also a good idea and try to stay in contact with your fellow survivors as much as you can. Everyone has useful skills, and you never know when someone's will come in handy. Some actions may require the use of more than what you have in the group, but the rewards are worth the alliance.
Avoid aggressive or territorial humans. Beyond being a threat to your safety, they usually draw a lot of attention to themselves. The more attention they bring to themselves the more zombies that are attracted to them, which they usually use guns to dispatch the zombies with, which draws more attention to them. Keeping a wide distance from these people will keep you from the larger concentration of zombies.
No pets. They may be your furry little family member, but having a pet along is one of the quickest ways to get yourself killed. To start, they can survive without you. Dogs and cats lived in the wild before humans domesticated them, and will be just fine after we're gone. Pets require specific transportation requirements, and can't be relied upon to keep themselves out of danger, no matter how smart you think your pet is. Furthermore, pets take much needed food and water without being able to properly contribute to the group. Pets can even actively get you killed by making noises at inopportune moments. Finally, people make bad decisions about their safety, and the safety of the group, when it comes to pets. If you can't live without your pet, don't travel with them. Find a place that can be heavily fortified, and only leave on supply runs.
Zombies are like cockroaches. For every one that you see, there are five that you don't. Never assume that you're walking into a handful of zombies. Zombies travel in hordes, and are never far from other zombies. One might straggle off to investigate a noise for a moment, but the rest will follow if there is a big enough disturbance. Approach every zombie as if they are a horde, because the rest may be just out of sight.