Best build archmage

Hello guys.
what is the best build for archmage ,both master of heavens and master of life?
Beside i want to know which stat point will give critical damage ?well some classess like shadow warrior and witch hunter have critical damage but i dont know which state point will give it to use it foe other clasess.

I put most of my points in focus for damage, the rest I split fairly evenly between wounds and accuracy, with a few in leadership for extra energy, though to be fair I have managed thus far just using a potion or eating something when my mana is low.