Rows: Well, the best way to do them is to start with the bar on the floor every single rep. Your middle back will have slight bend to it. You pull the bar off the floor quickly with the arms, and by a powerful arch of your middle back. You finish by touching the bar to your upper stomach or middle stomach. At no time is there any movement of the hips or knees, no hip extension at all, all that bends is the middle back and the shoulders and elbows.
This is hard to do and you have to have good muscular control to do it, or you'll end up straightening up at the hips along with the arching of the back. But if you can master doing them this way you will get a big back. This works because the lats actually extend (arch) the middle back in addition to other functions, just like with glute-ham extensions compared to leg curlsyou always get a stronger contraction when you move both the origin and insertion of a muscle, flexing it from both ends so to speak.
The bar returns to the floor after each rep. The bent row is actually best done as an explosive movement and the bar is moved fast. I have trained many people who could do this exercise with 350 or more lbs. I myself have done reps with 425, Ed Coan, who also knows how to do them properly, has done reps with over 500lbs without his back ever coming above parallel with the ground. That is stronger than Dorian Yates or Ronnie Coleman, by the way.