Check you inventory for each character you have quite often and
if they have any weapons or armour that they are not using which
is better than what they are using, then equip them with that.
Then pass the items down to other members so that they can use
them! This always helps me. Also when in a fight try and focus
all charcters on to one target. It will go down quicker. Then
hopefully you'll survive without the need of having to use Health
Potions!