R2:

Triangle - Thunder I
Circle - Blizzard III
X - Fire I
Square - Fire III

Up - Fire II
Right - Transpose
Down - Manawall
Left - Scathe

L2:

Triangle - X-Ether
Circle - Lethargy
X - Raging Strikes
Square - Thunder III

Up - Flare
Right - Convert
Down - Swift Cast
Left - Limit Break


This is what I use...although the biggest thing is that I'm used to it and I know and am comfortable where everything is. And this is used mainly as the level 50+ stuff obviously. Every now and than I may move something around but it's situational. That and I'm always up to reading/hearing other ways people have their set up.