/assist <p0>
/wait 1
/attack <t>Picks up whatever your party leader is fighting and attacks it. Keeps the whole party on one target without anyone calling it out loud.
The whole system in one macro. <t> is your current target, <me> is you, <bt> is your battle target, <stpc> prompts you to pick a player and <stnpc> to pick an enemy. Getting these right is most of writing a good macro.
/ma "Cure IV" <stpc>
/ma "Cure IV" <t>
/ma "Cure IV" <me>