Attribute Multiplier
Nord
Strength----1.05
Endurance---1.1
Agility------.95
Personality--1.0
Willpower---1.0
Intelligence---.9
Speed------1.0
Luck-------1.0
Given the same experiences/training a Nord is going to be stronger than a Bosmer. Just like given the same casting and etc a Altmer is going to be more intelligent than an orc. The multipliers would be very small so you can still have enjoy an orc mage. Currently at high levels the races become homogeneous making them feel little more than a change in art.
Another option is make race traits grow with level. For example the Khajiit scare humanoid at lv 40 should be much stronger than a lv one's. An Orc's Berserk would fortify/drain less at lower levels and later at higher levels the fortify would increase.
If you have other ideas to distinguish races even more, please do share.