Given my lack of tactics and strategy, my party build is probably an example of how not to do it: it was fun to play, but probably not very effective. I suspect the lack of specialising may have been a key factor.
Vometia: battlemage, single-handed tanky character with some aerothurge thrown in for a laugh.
Lohse: healer and necromancer, perhaps inadvisedly.
Sebille: archer and pyromaniac.
Ifan: archer, geomancer and thief.
