I've always loved the tempo-contrast method to maximize growth and improve the mind-muscle connection. It consists of alternating between slow and normal reps.
You start by doing two slow reps, then do two fast reps, two more slow reps, two more fast reps, and so on. Here's how it looks with pull-ups:
Tempo Contrast Pull-Ups
First Rep: Slow (6 seconds down, 3 seconds up)
Second Rep: Slow (6 seconds down, 3 seconds up)
Third Rep: Fast (2 seconds down, 1 second up)
Fourth Rep: Fast (2 seconds down, 1 second up)
Fifth Rep: Slow (6 seconds down, 3 seconds up)
Sixth Rep: Slow (6 seconds down, 3 seconds up)
Seventh Rep: Fast (2 seconds down, 1 second up)
Eighth Rep: Fast (2 seconds down, 1 second up)
And so on...
Ideally, you wouldn't have to do more than twelve total reps. If you can, add weight.