Two particularly egregious things to look out for:
YOU DON'T HOLD LONG ENOUGH -- Count a bit slower maybe.
YOU GO FOR TOO MUCH -- If you over-shoot on these, you may end up basttling with a progression where you can't quite hit perfect position at the top. That defeats the point of these. Go back a level and make sure it feels perfect.
Then, the errors from the standard Body-Row still apply:
YOU SHRUG – If you’re a modern day human, a modern day human with an office job, a modern day human that hasn’t been taught carefully in the gymnasium, then you’re a high risk candidate for shrugging on these. If you have forward head posture at all – you’re bound to shrug at first. The trapezius muscles will take over the move and your upper back may well be a bit lazy and uncoordinated…
The fix – extreme care and focus to keep a long neck, keep the shoulders down and to generate a mind-muscle connection with the upper back musculature and shoulder blade retractors. Make sure you feel the muscles working and make sure that you get your shoulders right back. Practice light, don’t try for too many and build up really slowly if you struggle at first.
YOU DON’T RETRACT THE SHOULDER BLADES – They should be squeezed back down and together. At the top of the move they should be squeezing towards each other and into the spine as the chest comes up. Don't just pull with your arms and be lazy with the upper back.
YOU DONT GET THE SHOULDERS BACK – If the above errors happen, the shoulders won’t have been pulled back enough. You must feel the whole glenohumeral joint (the bit the arm connects to) being pulled backwards.
YOU DON’T BEND THE ARMS ENOUGH – If you end up hands down by your waist somewhere, you haven’t let the biceps get involved enough. We want about 90 degrees of bending at the elbow.
YOU AVOID THE WORK – If the body doesn’t remain straight (typically the hips sag), you’ve subconsciously shifted your weight so you don’t have to lift it. The only movement should be at the shoulder, elbow and shoulder blades. Not the torso. Naughty.