@MCJ yes dude! me too, rear delts are one of the most neglected body parts out there. switch between hitting them on back days and shoulders days, do like 4-6 sets for them and keep the weight high, reps low.
thats what i did and mine have grown! they also really stabilize the rest of my shoulder especially when i do shoulder presses.
here are all the all the excercies you could possibly think of for your rear delts lol :
Barbell-
Rear Delt Raise
Rear Delt Row
Lying Rear Delt Row
Cable-
Reverse Fly
Seated
One Arm
Supine
Rear Delt Row
One Arm
Stirrups
Seated
Standing
Rear Lateral Raise
One Arm
Seated
Standing Cross Row
One Arm
Dumbbell-
Lying Rear Delt Raise
Lying Rear Delt Row
Lying Rear Lateral Raise
One Arm
Rear Lateral Raise
Rear Delt Row
Seated Rear Lateral Raise
Smith Machine-
Rear Delt Row
milk is for babies, real men drink beer - the oak