You'll need a low cable set at ankle height and a handle attachment. All the exercises are unilateral – performed one arm at a time.
A1 Rear-Delt Flye
A2 Face-Away Biceps Curl
A3 Triceps Kickback
Do 2-4 sets, 8-16 reps per exercise, resting 1-2 minutes before repeating the sequence.
You can certainly perform these exercises in any order you'd like. But since both the rear-delt flye and triceps kickback involve holding yourself in the bent-over position, it's best to put the curl between the two to get a break from holding the position for so long.
Move slowly through 2-3 rounds of 5 reps on each side to prep the shoulder before your next pull-emphasized training day that involves things like pull-ups.
They're one of the most difficult muscle groups to develop, but the cure to your underdeveloped hamstrings might lie in the answer to this question: "Which way do you point your toes during a leg curl?"