How many boxes?
2

What classes are you currently leveling?
Shaman / Paladin (both Draenei hotties)

What software/hardware are you using?
Synergy + G15

Any fantastic macro's you want to share?

I use the focus target to determine who my paladin shall follow. That way I don't need to be party leader to have her follow me or I can just switch her follow target on the fly depending on the situation.
[code:1]/focus target[/code:1]

Second macro obviously is the follow macro.
[code:1]/follow focus[/code:1]

The third macro I also used from the start, because I wanted the paladin to also do damage. Once I got the positioning down, I respecced her to 17 Retribution and the rest towards holy. Basically the paladin assists the shaman, casts Seal of Crusader and on a second press attacks the target.
The last line is NOT necessary, because if you have her on follow anyways, she will be facing the right way most of the time. BUT if you fight to mobs and after killing the first one, her positioning is off, this will make her attack the second one AND face in your direction. Also, she will only be on follow until she scores the first hit on the mob.
[code:1]/Assist focus
/Castsequence reset=20 Seal of the Crusader(Rank x), attack, attack, attack, attack
/follow focus[/code:1]

This one is no biggy either, but most of the quests can be shared, so you just have to get them with your main character and quickshare them with all your party. As soon as the quest screen pops up on the other chars, hit the hotkey for this macro and you've accepted the quest.
[code:1]/script AcceptQuest()[/code:1]

These now are very situational, but you'll get the idea of how to gain efficiency out of macros. Right now, I am not using those anymore, because I have become faster, but they really help a lot.
[code:1]/assist focus
/cast Hammer of Justice(Rank 2)[/code:1]

[code:1]/stopcasting
/cast [target=focus] Blessing of Protection(Rank 2)[/code:1]

[code:1]/stopcasting
/cast [target=focus] Lay on Hands(Rank 1)[/code:1]

PS: Once I get my twins to level 60/70 and my exams are done, I will write up a couple of guides for this page.