Friends are Fun: It is always best to PK with a buddy or two. In my opinion, I think PKing in a group of three is best. In a group of three, you can easily kill someone, and there's enough loot to share.
Tree hugging: This is essential to survival. This is kind of hard to explain, however, I will try my best. Tree hugging is when you are being attacked by many people, and want to get them to stop attacking you for maybe, two seconds, just so you can eat.
To tree hug, people must be followingattacking you. You then must go alongside a tree, and then go to the side opposite from where your enemies are on that tree. If you did this correctly, then your enemies should be stuck behind the tree.
For example, let's say you are on the west side of a tree. The people attacking you are one step directly south of you, hitting hard on you. You can then eat a lobster, then walk to the square directly north of the tree. If this works, your opponents should be either where you were before you tree hugged, or directly opposite you, on the other side of the tree. I hope this brief description of tree hugging helped. If you have any questions, post a comment, I'll try to answer it.
Hit and Log: It's an attempt at getting no-skull people to skull. For this you need a buddy. Both of you should be using the same weapon. Stand next to the victim. Either you or your friend can hit and log. This makes it look like the other person hit them, and the victim will hit back, making him skull. This rarely works, however, it's worth a shot. The chances of this trick working are increased when both players have similar names. Example: O O r4ng3r and O 0 r4ng3r.
Range-2h combo: This is deadly. This combo makes two hits appear at same time, making it very effective if you're going for the KO. Say you hit a 15 with range, then you switch to 2h and hit a 25, that's 40 damage! You can do this combo by ranging someone, and when they're at low health, you quickly switch to 2h, right after you hit them with an arrow, and then hit them with your 2h.
Food Potion: Heh... I couldn't think of anything better than the name of this tactic. When people eat, there is a delay in between bites. You can not eat 10 lobsters within a second. You can't even eat two. However, you can pot and eat a lobster in the same bite. This saves valuable potting time.