Playerkilling can be separated into a number of scenarios. But there's usually always a general rule that most people will adhere to: The person on the offense will usually be the victor. There are exceptions of course, as is the case with every rule, but this one is fairly hard to botch. If someone is attacking you, they likely know what they're doing, and have taken the necessary steps to facilitate your demise.

If you're ranking, travelling, just standing around, and someone attacks? Start running. Do whatever it takes to get away and hide for a bit. Getting away can be difficult if your opponent has set up the proper traps, but you should always be aware of what's around you, the terrain, and the options of retreat that are available to you, regardless of what traps you think your ambusher has setup.

You should also be aware of the commands that are available to you to assist you in avoiding ambushes. As well as little bits of knowledge that will help you high. There are certain strategies to apply when running and hiding, that depend on any number of things; class, race, areas, alignment, and so on.

You'll also realize that surviving PK (or just outright avoiding it) in the lower level ranges is much more different than the upper level ranges. Lower level ranges have to respect the guards of every city, and has to be aware of the aggro-level-cap (some mobs will only aggro on PCs BELOW a certain level), etc. While high level ranges don't have to worry AS MUCH about these circumstances.

Eventually, you'll come to the realization that there actually are a lot of things you can do to avoid dying. Once you begin to figure out how to avoid death, you'll find things start to go easier as you level higher. Most people actually don't want to put forth the effort to finding people who are adept at hiding. The longer you live, the better equipment you'll eventually get, which ups your chances of survival in the hero range.