[Originally posted in exploits, moving here]
Alright, just trying to contribute here. My friend and I were leveling paladins together with the heirloom shoulders and other heirloom items, I was holy specialized and he was retribution. I had about a level ahead of him in experience so we decided to try to leave group and have him gather up a ton of mobs in Hillsbrad farm.
All I did was heal him through it (set him as focus for easier targeting when he was running around) and he was easily getting 5-6 bars per pull we did. It also helped that I was at about 100 Spell Power at level 25. (Now 200 spell power at 35, all we do is Area of Effect (AoE) pull now and we've leveled 20-35 in a few hours then called it for the day.)
With a higher level character healing the characters experience gained will be slightly diminished, but as a low level character healing another low character (with imbalanced gear to make the pulls possible) you can get fast experience on a weaker character with out any extreme methods. Hell, all he did was stand there and concencrate with retribution aura and got tons of experience.
I know decent low level Mages can solo a few small pulls like this, but nothing like what we were doing. We pulled the whole bottom farm patch and the whole orchard and just watched them all die.
-Note: If you didn't catch this the first time, what we're doing is one person getting the full experience instead of sharing it, thus gaining experience faster.