My fire mage has two main dps macros. One is for use when the target is going to live for a while longer and the other is used when the target is going to die within about 6 seconds or so.

The one for targets that are going to last for a while is as follows:

/console Sound_EnableSFX 0
/cast Combustion
/click MultiBarBottomLeftButton1
/console Sound_EnableSFX 1
/stopmacro [exists,harm,nodead]
/assist Isochor
/assist Adiabat
/cast [nocombat] pyroblast
/cast scorch

And then in slot 1 of bottom left action bar I have the following macro:

#showtooltip fireball
/castsequence [exists,harm,nodead] reset=12/target fireball,living bomb,scorch,pyroblast,,
/cast [combat] fire blast
/use 13

You can spam the first macro and it does all kinds of goodies. The sound effects scripts are so that I don't have to listen to annoying messages when playing the mage solo. It casts combustion and one of my trinkets whenever they're ready. The reason for the two assist lines is so that his macro still works when the normal leader isn't there. If he's not in combat, he opens up with pyroblast. If he is in combat, he starts off his rotation with scorch.

The double comma at the end of the castsequence is where fire blast fits in. The double comma thing is so that he will continue with his rotation and not get stuck on fire blast if he's not in range to do it. Also note that I put enough things in the castsequence to make it longer than 12 seconds instead of exactly 12 seconds. My mage has a few spell haste items, so if I didn't make it longer than 12 seconds the pyroblast would be wasting a tick and the living bomb wouldn't detonate before being reapplied.

Also, this macro is set up in such a way that the mage only assists my tank if my mage's target is not a living enemy. This way my tank can switch targets and my mage will continue to attack the same target.

Next is the macro for attacking enemies that are very close to dieing:

/console Sound_EnableSFX 0
/use 14
/castsequence [exists,harm,nodead] reset=8 scorch,,scorch,scorch
/cast [exists,harm,nodead] fire blast
/console Sound_EnableSFX 1
/stopmacro [exists,harm,nodead]
/assist Isochor
/assist Adiabat
/cast scorch

This macro works the same as the previous, but with a simpler rotation to only include spells that are better for short term damage.

Finally, one more macro is needed. This last macro is to fire off the extra pyroblasts from hot streak:

#showtooltip
/cast [exists,harm,nodead] pyroblast
/stopmacro [exists,harm,nodead]
/assist Isochor
/assist Adiabat
/cast pyroblast

I use an addon called Power Auras to notify me when my mage has a hot streak. When hot streak procs, a big fire icon lights up on the screen of my tank, accompanied by a special sound. Power Auras is an excellent addon for keeping track of procs on your followers.


Edit:
I completely misread your original question. I'll leave this here in case your interested.