I have gearset swap macros that automatically sort my armory as well which I place in two vertical hotbars along the left-hand side of my screen. I probably use those most often.

I also have a macro set up for Eye for an Eye that specifies <tt> rather than <t> so that I don't need to change my target to hit the tank with the buff as a BLM.

I typically try to stay away from macros that can combine multiple abilities as there's always the chance that lag can cause them to miss a step and the timing is not as accurate as doing it on my own. I do have a Raise macro that will check for Swiftcast before Raise, but other than that, I prefer to use macros sparingly in combat.

I might set up a macro on convert that will default to use a mega-ether if convert is down, though.