Poison + fire = explosion, so fireballing an ooze barrel is nice,
or creating poison with an area including a torch creates a nice explosion..
killing certain of the elementals (not sure if it's all of them or not) creates a small surface, so e.g. killing an air elemental (through any means) standing in water/blood will electrify it, fire elemental in poison will cause an explosion etc.
I find smokescreen (pyromancy) to be a really handy spell (aside from the good blind chance with high int), delay your warrior and create a smokescreen so all of the enemy wastes their AP walking through it instead of causing damage/CC from afar (also a nice way to get ranged enemies closer to your melees).
And firefly is also great, use it to unfreeze your guys or annoying slippery terrain, burn a load of enemies at once, make the enemy think twice about running to hit your mage, and it will also create steam (which can be electrified) on the way if it hits water, and explode poison. Amazing utility spell all in all.
Far-out man also increases the range of both of these spells by 2m which is great.
