That pretty much sums it up, though there are a few things I would add.
First, if you like to get all your characters some AP for the fights leave Tidus and Rikku in at all times but just switch out the third person using each of the characters' overdrives.
Second, make sure each character has their overddrive full, also make sure your most powerful summon has their overddrive at max and that would most likely be Valefor since his overddrive is non-elemental
and Third, you might want to save your most powerful overddrive to deliver the last blow in hopes of getting an overkill
That's about all the things I did in addition to the afforementioned strategy. I hope all this helps.