I went through that about a month ago with my first wow accounts ever. It was indeed bloody slow. Now just started doing it with my 2nd team and it goes way faster, is less boring, .. a couple of things that work for me;

- it's o so worth it to have a tank, if you have raf/granted levels left, make a pally and boost it to 70. The 1-2 days boosting is well spent.
- i've spent a day to make myself a db, for every zone in northrend, basically copy/paste from thotbott and then check each quest / chain ... is it collection, is it kill, ... skipped as much collections as possible.
- i queue for AV all the time, it's entertaining and gives decent xp. at lvl 73 you start to be valuable in this bracket as a mb
- i run instances a bit below my level, gives good xp and it's pretty fast
- so far average played time per level is about 4-5 hours
- the mix of av, fast questing & instances works very well for me
- my goal is to reach 77 as fast as possible to reach northrend, the last levels are very fast

gl