For Thunderstorm, I use this macro:

#showtooltip Thunderstorm
/cast [mod] Elemental Mastery
/stopcasting
/cast [mod] Thunderstorm
/castsequence [nomod] reset=45 ,,,,Thunderstorm

Actually this is the macro on my 5th Shaman, just change the castsequence order for each of the other shammies.
Pressing the macro will round-robin your Thunderstorm, if you're using it for control.
Any mod (shift/alt/control) with the macro and they will all Elemental Mastery - Thunderstorm (assuming its not on cooldown).

So the macro gives you the option of control/defense and damage/burst.