Most efficient way to level when 5boxing?

I'm sorry if this is a repostx100. And if there is a sticky somewhere that explains this please link it.

Okey, so while waiting for my new computer im browsing this site pretty much, so I'm prepared when I start playing.
My question is what the best way to level is. I got good knowledge in how to level single characters, but my guess is that 5boxing is a whole lot different xD

Instances all the time? Questing? Grinding random elite mobs?
I was thinking that I should do almost all instances atleast once to finish all the quests in there.

And while I'm at it, is 'warrior + 4xshamans' a good combo?

Essentially:

Questing in Instances > Kill Quests > Instances > Other Quests > Collection Quests

Questing in Instances - You get XP for the mobs, good XP too & XP + rewards from the quests.
Kill Quests - Good when you can find them but I don't think it'd be possible to level all the way up with just these.
Instances - Good XP from mobs.
Other Quests - Providing you know where the pickup and drop off is and can do several things at once they aren't bad for XP especially once you hit 30+ (I had 2330xp for running across a camp for one delivery quest).
Collection Quests - Actually give good XP, but unless you have a very good setup for dealing with looting/per character they are a pain to do. Plus unless each mob drops the item each time you end up killing vast swathes of mobs... Only really good if the mobs are elite.

Hope that helps.

I have made good progress pulling four of my toons with one 70 from 23 to 40 now, in hour per level or so, first in the stockades, then in SM. I think the key is to look at the XP formulas. You get Ok-ish XP while the mobs are between your level and nine levels ahead. This is with a 70 in the party lowering your rates.

of course the question is if you want to play your team pure or boost yourself =]

I just dinged 4 of my 5 shammy team to 50, 1 is still hanging out at 40. I agree with the above poster. Here's what I found:

If you have a 70, take your 70 and 4 of your multibox team and just let your 70 own the instances over and over. Your guys will get full xp for each kill. You can do the quests as well, but I'm pretty sure that grinding instances is going to get you the most XP/hr. This is what I've found. I did a mix of questing and instancing up until 35ish where then i exclusively ran instances all the way up to 48. My plan is to just go and solo level the 5th man that happens to be on my main's account so I can't power level him just yet.

Also consider that even if you are extremely efficient with your questing, mapping our your path and using all the questing helper addons, you will still be slowed down by people wanting you to explain what you're doing. In instances you hardly ever get noticed and as such things are a lot faster and you have a lot more freedom to stop if you need to, adjust your macros and such, without worrying about someone coming up and harassing you.

I run 5x shaman, but I've read numerous times that pallys make better tanks than warriors for multiboxers given their efficiency tanking multiple mobs at once.

Its boosting:

Mage boostign madness. (lvl: 61)

I have a 70 warlock I guess I could use for boosting. But if I do instances with him killing everything easy, my 4 lowbies wont get full exp will they?
I was thinking of creating 5 fresh characters. I choose warr over pala becuse I have always wanted to play warr :P