I'm level 29 (halfway to 30) and my build is basically:
Conjuration only has the first perk in it
Destruction has Novice and Apprentice perks at half cost
Illusion only has four perks in it, last being the one where I can cast silently
Two-Handed has Champion's Stance and Barbarian (2/5) perks
One-Handed has one perk (for a little extra kick for daggers)
Archery only has two; Overdrawn (2/5)
Sneak uses up the rest of the perks, being almost full.
I have a few more left over that I'm going to put into Conjuration.