I'm always as soon as I can in every zone and don't finish chains if I just have the level to go elsewhere.

I've been following this guide from day 1 of WotLK (yes, it was already uo day 1 ).

wtbblue guided me but it's unfortunately gone.

Here's my route:

Howling Fjord (68 – 70)
Dragonblight (71)
Grizzly Hills (72 – 73)
Zul'Drak (74 – 75) - I try to get 76 as soon as I can because Sholazar it's great and the highest speed you can have on questing. So I either stay a bit longer in Grizzly Hills or Zul'Drak.
Sholazar Basin (76)
Icecrown (77 – 79) - I do Argent Crusade + Crystalsong quests, then I go to the Zep, do Ebon Hand and by the time I have no more quests I just have a few xp left to ding 80.
I head then to K3 and in less than a dozen quests it's over.