Untill level 50-55 (when you got good ES-chest and rainbowstride), you should progress as life + ES build. When apr. at level 55 switched to CI (you should take CI when coming to the left side of Act2 Miracles (clean the right one first) and you'll be around 55-58 level till that time.)
As for level progress - focus on flat physical dmg and ES (maybe some life nodes as well, you'll just re-roll them later), when on crit and block.