That V Shape
This helps achieving a V shape look. Shedding a lot of fat on your waist. The smaller your waist is, your back will look more impressive (well that V shape). It's also genetics to have a wonderful back, but forget about genetics. Just go all out and some kind of results will come. I prefer working my back from top to bottom. So I work traps/midback first, then lats, then lower back.
Here's a back routine:
Barbell Shrugs x 8-12
Cable Rows x 8-12
Wide-Grip Pulldowns x 8-12
Close-Grip Palms in Pulldowns x 8-12
Back Extensions x 10-15
I didn't put in the amount of sets, because everyone is at a different level of lifting. Some people can tolerate only 6 sets while others can tolerate 20-30. So use what works for you.
I try to do less sets as possible. I rather do 2-6 sets of an exercise and go all out instead of doing 6 sets hardcore and on the 10th set my muscles fail to contract. That's just called over doing it. If you get to the point where you muscles won't contract, then stop and call it a night. No point in beating a dead horse. Also definition is good for the back. Once you have some muscle to show, then lose some fat and harden up.