Although I had a paladin tank with my 4x elemental shammies, I didn't AV at all and only ran a few instances to get to lvl 77. UK 3-4 times was it. I quested entire BT, HF, and DB.. all on rest xp. That got me to around lvl 75. Then I did some GH (especially the dailies!) and a decent chunk of SB to get to 77, and once you get cold weather flying at 77, it's a cakewalk to 80.
Once you hit 77, do this:
- Get cold weather flying.
- Do Sons of Hodir quest chain to unlock Hodir dailies. (a couple of quests in the chain are a pain in the ass, but they're worth it.)
- Do Argent Tournament quest chain to open up dailies. (these are quick!)

Each day you can do this list of dailies, which provide a bunch of quick XP, gold, and something specific you'll need:
- GH PvP dailies. (I do all except the ones requiring fetching the bomb). XP, gold, and venture co currency for totems/cloaks/trinkets.
- Sons of Hodir dailies. (I do all except the anvil quest - that one sucks) XP, gold, and Hodir rep for shoulder enchants.
- Argent Tourney dailies. (I do them all. The weapon one can suck if you have different races in your group.) XP, gold, champion seals, faction rep.

That's roughly 13-15 dailies at 20+k xp, 7+gold each, and they won't take more than an hour or two max. Once you champion a faction at Argent Tourney and open up Hodir revered quests, you'll be able to do nearly 20 dailies very quickly, provide some easy epics and heirloom gear through champion seals, and get at least 400k XP and 140+g (per character) per day for around 2 hours of work.

70-77 was a long grind. 77-80 was EASY. My next group, I'll skip all collection quests in BT/HF/DB/GH/SB that I can, and go purely for quick quests in *all* zones while focusing on quick dailies first.

Edit:
The jousting dailies are easy once you figure out that you can dps your opponent on foot from your alts while your main does the jousting. You still have to do 3/3 and 4/4 for each character, but at least you can dps from the others. I save these dailies for last if I have some extra time since they are a bit more tedious than the others.