I just finished leveling 5 shamans from 60-70. I did all the non collection quests in HFP, then at 61.5 started running all the way through ramps a few times, then at 62 I went to zangar, finished all the quests there that weren't collection, then ran BF to first boss until 63.

Also tried running SP to first boss a couple times, by now I was 63.5. Went to Terrokar and did all the non collection quests there, made sure I was up to 65 (think I had to go back and run SP once or twice more). At 65 I went to nagrand, finished all the quests there, hit 66, did ring of blood, durn, etc now that I had earth elementals. At 66 I ran mana tombs a few times because 5 shamans makes it easy. I think at this point I was 67 and went to BEM, finished the non collection quests there, by this time I was probably 68, did all the quests in SMV, ran sethekk halls a few times, hit 69, and was sick of instancing so I went to netherstorm and finished quests there until 70. I was thinking I would finish netherstorm quests for money but the QD dailies are so easy/fast I'd rather just go there once a day and do 8-10 quests for money.

And there you have it - 60-70 as 5 shamans.