2. Dirt/Firebreath are the gift that keep on giving. Simple advice, but worth it. Provides both offense and defense. Use them early and often. I would take a flaming socket over almost anything else, perhaps even curse, depending on the target.
3. The waiting game: when you fight is a huge factor. Be the decider of when you engage, and time your opponents buff spells. Duck into their area with no intention of fighting, just to have them spell up. Return a few ticks later. If they are coming for you, run for a while without your buffs up, as they will probably have spelled up before the chase. Etc. By being cagey in this manner, you will frustrate them, burn their consumables, and increase the chance of them losing a key buff in combat. Detect magic is invaluable here. 2 ticks on sanc or something else key is the perfect time to engage. If you are the target, you have the advantage here.
4. Chasing for the lazy: I'm a very lazer pker. And I am awful at chasing. I never even bothered to learn the underdark or any expansive areas (except winter). Yet I was once accused of having chasing triggers for when people fled from me in combat because I was so close on their heels. Its easy to do...fight in places with minimum exits if you anticipate to overpower your target in the SHORT term. Knight Canyon is great for this. Conversely, if you anticipate being overpowered in the short term, fight in Elium. Lots of exits, lots of mobs to screw scanning. For the more advanced, you can even time this strategy. When your opponent is almost dead, don't hit that last bash or trip. Wait for them to flee and if you only have to choose from 2 or so directions you should be able to catch them and perform ANOTHER bash/trip before they recover. This maximizes the effect of the few exit fleeing penalty. You'd be surprised how many extra kills this nets you.
5. Know the skill level of your opponent: its like poker. You must know how they will react to your strategies. Some advanced chasing strategies won't work on newbs, and vice versa. Perfect example...someone flees into a shop in Val Miran. They must run back past you to get out. Against a newb, you don't move, you just spam bash. Against a shaky vet, same thing. Against a strong vet, you chase, because they will just sit there with the down direction waiting for you to walk in (at least I do).
6. Know their strategy: whatever class you are fighting will have a dominant and secondary strategy. Combining this with number 5, you should know what your opponent is going to lead with or throw at you very quickly. Prepare for this. This is beyond being poisoned for sleepers. There's a counter to everything and a counter to that counter, and so on...so realize what part of the spectrum the next battle will take place on and exploit it.
7. Command timing: never stack commands. Refer to number 4 for an example of command timing, but it is key to enter a command only immediately before it will execute. Takes practice, but increases your kill rate on opportunities and flaws when they present themselves.
8. Multiple stage strategies: not every battle has to be decided in the first skirmish. Many aren't. You don't even have to WANT it to be decided in the first skirmish. For tough opponents, multi stage strategies are important. This includes focusing on killing mobs first, or destroying weapons, or making them use powerful spells with longer cooldowns first while focusing on staying alive, and then switching to a more aggressive style at the appropriate moment. Classes vulnerable to this: necros, vamps, clerics, rangers, etc.
9. Character creation: many people won't agree with me on this, but I always start with a pk combo in mind and then create an RP for it. In an ideal world we would think of an RP and then build it, but the practicality of it is that everyone gets frustrated if they die a lot, and you can't play a grizzled but bad arsed dwarven warrior if you are getting spanked every other battle. With that in mind, choose race/class combos that compliment against the widest array of opponents (less so the case as the player base diminishes). That way, you won't have those one or two enemies who keep making you have to equip. For example, if I was ever to roll another character, it would be a minotaur warrior gladiator. Warrior gladiator to defeat melees and hybrids, mino charging gladiator to defeat mages. Well rounded. Or, undead shaman. Immune to most shaman weaknesses, and opts out of some key enemies. Or, watcher thief. Again, rounded. Just my 2 cents on it.
10. Consumables: always carry multiple! vial of sparkling liquid (0% fail rate for that situation when you cant afford for your staff to fail), pill or potion of teleport (theres a teleport potion you can see while blind, get it), herbal brews, and a garlic serum. Always.