In an attempt to enjoy all the content BC has to offer I am trying to complete every quest (within reason) I have before moving on to the next area.
Now of course from the start this may not be a very good plan of action, considering hundreds of other players are vying for the same mobs I am. I'm looking at you Hellfire Peninsula!
Some of my guildmates simply skipped Hellfire altogether and didn't spend much time in Zangarmarsh either, just to get away from the crowds. But I have a tendency not to go back and do old quests if I didn't do them the first time around.
WoW seems to do a good job of having NPCs move you on to the next area when its appropriate. So I usually have a few quests in the next area before I finally finish up the previous one.
Some players just grind on mobs only doing quests if they include the mobs they are grinding on. I did that when I was trying to "powerlevel" an alt. Doubt I'll do that again - its really boring.
Albion Farms and focus
15 hours ago