After hunting a bunch of giants for multiple levels on 3 different characters, this is my advice: If you are a melee type, get invis'd, ported, whatever.. just get someplace else. solb, CS if you can, wakening lands, whatever. Get somewhere, and get experience, level up.
If you're a necromancer, enchanter, shaman, magician, or bard.. level up, same as above.
If you're a druid.. haha. See if you can mouch off people hunting giants, or dot kite from like level 38 - 45 in GD. Everyone else though, once you level up, come back to Great Divide and just slaughter EVERYTHING you see. Elites, scouts, whatever. Just kill it.
If you break it down and it turns out that you solo, or you and your merry band of giant killers, only manage to fell 8 giants an hour -- that's a LOT of hours to get good enough faction. On the other hand if you're a 55 monk, 49+ necro, etc..so on & so forth, you just come back and kill every giant you can find and will probably kill a few hundred giants in a single evening, raising faction a lot quicker.
Some people express concern for level difference vs faction gains. While I am no expert on this issue I will say that I've had level 51 characters gain CoV faction from drakkel dire wolves in the great divide.
Not to mention that any other zone you could be hunting can very well have much better drops..
Unless you're one of Jerry's kids and run around with some army of everquest players that never leave their computers, you probably won't readily be able to just stroll in Kael Drakkel and start collecting faction.. soooo...
Just my opinion though, and what do I know, I've only been around longer than half the verant customer service department (start date April 17th, 1999)
--Annonymous and unscathed