Pk, it varies from charactar to character and map to maps. do not expect to become a good pker by reading the suggestions posted here because a good pk need pure experience, skill and preplan.
guidelines
1. Be a solo hunter.
2. Learn to manage your parole.
3. Do not trust any 1.
4. Do not call your friends to clean your crap.
5. Always carry larcs.
6. Uncheck all your options except whisper.
7. Do not go to pk in your noob armor. (guse why?

)
8. Never cheat your opponent(eg.deal). You dont want to attack a person when his hands are tied right?
9. Never abuse( got a good reason for this1 too

)
10. make good use of environment.
11. Dont be a stupid macho.
One pk story.
1 Afternoon, a cafe in pune, a drunken g4 warrior in R4 took a party (g4 g5 g6) of a g7 mage. The party was totally screwed up and the G7 mage had to call G8 warriors and hks to protect her party from the warrior. Even though the warrior was killed many times he kept pking the party unless he got murder status. (his exp came down to -46 from + 64)