Many submissives have a dichotomous relationship with being Dominated:

On one hand, they can be fastidious, dedicated, focused, and unyielding in the face of adversity.

But on the other hand, they can be finicky, wishy-washy, unreasonably preferential, and living more in fantasy than reality.

Dominance should optimize. A good Dominant will use a submissive to the best of their ability; a smile will creep across His/Her face when the slave has done an impressive thing. A great Dominant will take the time to figure out the aspirations of the slave, and use them to achieve that end. A primary focus for a truly wonderful Dominant will be to push the slave to accomplish every goal, hit the bucket list, become a far better creature (and therefore a better tool for the Dominant). 

Dominance should enhance. Physiological health should improve - fitness, emotional well-being, endurance, strength, and ultimately longevity. A puny, weak, emotionally unstable slave does no good for any Dominant. I don't Dominate children, animals, or the mentally incapacitated. Why? It's already established that they're below the capacity to benefit from My Dominance and are clearly not a challenge. I don't Dominate a wet blanket, either. 

Dominance should benefit. Despite the seemingly selfish nature of a Dominant in popular culture (and poor executors of Dominance), a good D/s relationship at the least should be beneficial to both parties in some perceptible way. Minimum. A great D/s relationship will create a comfortable positive dynamic where both parties feel more in control of their lives during their interactions (or comfortably out-of-control for slaves who enjoy that). A wonderful D/s dynamic is similar to a "power couple" - both parties will achieve their dreams and become integral parts of each other's continued success. 

Should any of these fall out of balance, a Domino effect is created - and everything falls apart. But always remember: Dominance should optimize, not erode.