Install and XP per hour deal, like fu_experience for example.

Figure out what instance you can do easiest with the minimal amount of higher level characters at walking speed. Enter that instance with your low level character and the above subset as soon as you can zone in using the following webpage. http://www.wowwiki.com/Instances_by_level

So at 35 you do ZF and murder even elite mob you see. I usually ride mounted past the fountain, take a left to the first gate/arch and then head back to the instance portal with the mobs in tow behind me. Then we both mount up and head to that same gate/arch and I do the up to the hydra area and head back to the gate/arch. Then I do 100 trolls event quick and reset.

So at level 40 you can zone into BRD, likely with one or two of your other characters you can tool on the mobs in there handledly (the training route, two prison routes, arena and a quick emp run). You need to get a pace set for how to burn down the mobs quick. If your OOM you need to bring in another shaman and look what the hit to the XP is.

I BRD I walk someplace without aggro and then pull a few pulls worth on me, the problem are the net they spam at you there so you cannot go crazy and pull too far.