although I have already talked about chest flies in a few videos, this one is going through details of cable fly. the basic fundamentals are the same: keeping the wrist straight, bending the elbow slightly while holding it that way during the repetitions, no bending of the neck, squeezing the handle hard, keeping the shoulders back and steady, breathing with a rhythm, and controlling the speed.
aside from these factors, there are 4 things you should consider:
1_ how you position your own body before you start
2_ where you put the pin(cable height)
3_ what degree of abduction/adduction your arm has
4_ what angle the cable has compared to your arms