I'm not quite sure if you're asking specifically FFT, or just games in general that have quite a vast array in the ways of personalization.
Well, I'll talk about Dragon Quest IX as I've played that game for what's nearing a total of 1000 hours.
To begin with, it really depends on the game how I plan to build my characters, but most games, while allowing multiple characters, there's (usually) only one real way you can really build each of those characters (sadly). DQIX is one of those games where nothing is really indefinite aside from your main character always being in the party. Aside from that, you can choose to have anywhere from a 1 - 4 person party, whether or not you play with your friends, what skill points you assign to what skills first, and how lucky you are in obtaining some legendary type weapons and finding permanent stat boosters. Not to mention your character's class.
Now, in DQIX, I tend to go solo (unless playing with friends, and even then we do our own seperate things), so a good balanced class is the way to go.
I used to use the Armamentalist class, as they learn a fair few buffs and debuffs in the way of spells, and they can equip what seems to be the widest range of armour, so I don't need to fret much about whether Ior not I can wear something. Not to mention their special attack increases EXP gained from battles (even bosses). They're pretty good, AND they learn the spell Oomph which increases attack two levels (aka doubles your attack).
However, as time went on, I found the later grotto bosses to be rather difficult, and classes DO have set stats they get to that's essentially divided up per level, so there wasn't much hope for improvement without massive hours of grinding on enemies for them .5% or less drops of permanent stat boosters (which stay forever even upon reseting to level 1 +#, but stick to that class you use it on).
I discovered that though the paladin class lacked agility, pretty much ALWAYS going last, they could take a hit easily. Upon my discovery of this, I stopped using the Armamentalist (though I still love that class).
Eh, I feel like I'm getting off track or something, lemme sum this up.
Essentially since I go solo, I'm naturally needing more HP and defense. Out of the 3 main physical characters, they have the lowest attack (though they by no means have low attack), but they have the highest defense, and their HP naturally will reach 900 (on the dot, actually, and that is, if you have all the hp boosting skills). Not to mention, the special ability of the paladins is that they can become literally INVINCIBLE for 3 turns and draws the attention of all enemies towards them. This also helps when fighting foes with my friends.
And in the end, they also get midheal (which, since in this game your magic boosting stats actually matter, can get pretty high. it's base healing is about 70. I heal about 150-200 on average), and they can get the buff named "buff", which boosts defense one level (able to be stacked one more level, invincibility through massive defense anyone?).
So, I guess I like to make my characters immortal. Another example being FF12, and that I got the zodiac spear as early as humanly possible without cheats. Then I went grinding. For a long time. In near end game areas. I was level 50 or 60 in a point in the story you were probably only supposed to just be turning 20s. Needless to say, I've been defeating every side-boss I can find. Hellwyrm, The fat green thing in the sewers, The great white chocobo, all o' them be dead. I think I'm just getting to Arcadia. Or whatever that place is called. Maybe...NO, I'm like in that crystal thingy later on where you can find ultima. Guess who's my next target.
dOn'T MiNd mE! i'M jUsT CoNtAgIoUs!!!
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