Hey,
Having played quite a few rounds now, our group noticed the following: Most of us picked the same spells for our wizards, if the school wasn't opposed (elemental bolt, telekinesis, teleport, mind control, etc...). That resulted in boring matches, where 80% of the spell's being used was telekinesis (and yeah, we did have LOADS of terrain still). So we decided to introduce the following rule: For every spell school we piced the two most useable or iconic spells were now only avaible to you, if you choose a wizard of that school. Grimoires of those spells could also never be purchased and can only be found as treasures. So only a Necromancer could raise zombies, only an Elementalist could cast Elemental Bolt, only a Soothsayer could mind control others...
As a result we got much more interesting games with loads of spells being used that we never saw before. Also it wasn't so frustrating anymore that everyone just knew or could simply buy your most powerful spell, which made your wizard feel kinda unspecial.