Mage points into 'Mighty' (In the Ritual tree)

Warrior points into... hm pretty much all of them are useless in my opinion. I would say, 'Spellshield' in the ladies tree is a good universal thing. Honestly, you can't really do any mistakes there.

Thief points, there are many interesting things you could do. I'd recommend starting with putting things into 'Warlord' (Tower tree) it will decrease the cost of stamina abilities by alot and it will make a huuuuge difference. Since you are wood elf, 'Mooncalf' will have a big impact either.