I will share a little knowledge I have built up on how to nickle and dime your opponent during that critical magic phase where you desperately need buffs.
1. On average, a level four wizard should be able to cast a spell with a casting value up to 11 with only two power dice. Don't throw away dice, "Just to make sure you get it," because if you have a die advantage, you need to press your advantage till the very end.
2. Always start out your big turn of buffs with one dieing warrior priest buffs. There is a 2/3 chance that you will cast the spell successfully, and if their level four fails to dispel, you have gained much more than a re-roll to wound. Usually my opponents will let the priest buffs through in order to block the bigger spells they think are coming.
3. A power stone on a level four wizard can give quite a nasty surprise to an unsuspecting opponent.
4. Luminarks are worth their weight in gold for that +1 dispel die. Especially when you cannot roll to channel.