I posted this today in another thread.. but it's relevant here.

This is what I do, and have been doing all week with my new RAF groups. ( I am Alliance, horde must substitute their own lowbie instances)

10-15: Deadmines - move alts to the first boss when you kill him, stay there until second boss is dead etc. Leave them at the mouth of the final cave for all the exp and then collect them for the run back (through the instance, it's faster than going outside again)

15-23: Stockades - Don't move unless you are getting / turning in quests

23-33: SM Cathedral - Yes, I move them to the first door, and then leave them there the whole instance (you can pull the last boss out of the cathedral to get full exp)

33-42: Scholomance - Move alts 10 feet in to the area with the quest givers. Then stay there for the second-best boosting area in the game.

42-48: BRD - I usually just follow my main through the instance. Be careful of patrols, they will one shot a fresh no gear no talents lvl 42 lol.

48-57: LBRS / UBRS - For LBRS, I clear the first room (patrol and the pack at the back) and head to LBRS with my main, alts following. Then I drop them off at the first ledge you see in the main .. area of LBRS (you will see on the video) Clear LBRS, and then I follow my main through UBRS, but staying a boss behind, so they dont pull aggro and die so easily.

57-63: Hellfire Ramparts - nope.. enter.. kill.. leave repeat. then WAIT a long time because instance timers will ramp up fast.

63-65: Sethekk Halls - Yes, follow the main again staying one boss behind, so you don't pull aggro when you are new. (You CAN skip this if you like, but it's actually faster to go here than to slug through another instance lock of Hellfire to get the last couple levels in there.

65-68: MAgister's Terrace - I move my alts to where i killed the first set of mobs, and then leave them there. GREAT EXP!!

68-71: Utgarde Keep - I have my alts auto-run about 20 seconds after my DK, so they both just basically auto-run through the while instance. DK stops to kill, but he has unholy aura, so he's faster anyway. This is a good spot to stop boosting.

71-80: Quest.. or Dungeon Finder if you have enough gear and an appropriate group (I never plan that far ahead, and I'm always naked when I get here haha) I find questing from 71-80 a lot more interesting, since you no longer get a lvl or two per run, I find grinding UK and other WotLK instances really REALLY boring. And if you have RAF... it's really easy and you can skip most collection quests.