As I've mentioned in other posts here, I took the LOONG way around.
After I got out of the DK newbie area, the first thing I did was go around pretty much the whole Old World and look for "breadcrumb" quests that point you to other cities/zones and did all of those. I did that so that those breadcrumbs would be counted for the Loremaster achievement with no chance that I would do the actual quest the breadcrumb was leading me to and thus lose my access to the breadcrumb quest. Note, however, that I did NOT do the quest the breadcrumb led me to. Once I turned in the breadcrumb quest, I left and came back for the actual quest later.
THEN I went to Elwynn and started in Northshire Abbey with the newbie quests. Once those were done, I did the same in Dun Morogh. I then worked my way up zone by zone in Eastern Kingdoms, from the lowest level zones to the highest level, consulting WoWhead and a couple "easy to miss quests" guides as I did so to be sure I was being thorough. By the time I was done in Eastern Kingdoms, I had Loremaster of EK done, and I was exalted with everyone in the Alliance except Exodar and Gnomergan (I could've had Gnomer except that I didn't do the Gnomergan instance quests because 1) they don't count toward Loremaster and 2) I despise Gnomergan even when I'm high enough level to make it trivial.) I also ran Strat and Scholo a number of times and wound up exalted with Argent Dawn.
Then I went to Kalimdor and did the same thing, starting with Teldrassil and Azuremyst and working my way up. I had my Ambassador title before I was finished in Ashenvale. By the time I was finished in Silithus, I was lvl 66 or 67, had Loremaster of Kalimdor done, was exalted with Timbermaw and Cenarion Circle, and was revered with all four Steamwheedle Cartel factions.
Once I hit Outlands, I decided I wasn't going to worry about hitting exalted reps with anyone who didn't have non-instance dailies or item turn-ins to do. Again, I started in Hellfire and worked my up. I used the Loremaster achievements as a gauge for how thorough I was being in my questing, but if there were soloable quests left over after Loremaster was done, I finished them as well. I didn't worry too much about group quests or instances or loot, because I was so high level quest rewards and loot really weren't relevant to me. I'd have a blacksmith friend of mine make me some armor once in a while to upgrade and that was about it. By the time I finally finished in SMV, I was 77.
So...I started Borean Tundra at 77, I'm not 79 and still working my way through Howling Fjord. As someone pointed out before, the money I'm going to be making off quest rewards for almost all of Northrend is going to be incredible, since I'll likely be 80 before I get to Dragonblight.