For your arms, focus on contraction and recruitment. It'll make a world of difference. Each rep of each movement, focus on contracting and squeezing the target muscle. Feel your tris contract and bunch at the back of your arm during rope extensions, hold at peak contraction for a sec before lowering the stack. Keep your hands cocked back during curls and squeeze the **** out of the bar.
There are tricks are optimizations for just about every body part, it's just a matter of finding what techniques work.