Dont be scared of the DL - if you're benching and squatting then it should be straight forward and is a complimentary exercise. Just start light, watch yourself in the mirror, ask some to watch you/film you and go slow.
I find a mirror from the side helps with correct posture in the beginning. When you learn what right feels like after seeing what right is. Obviously only very light at a twisted head will fuck things up fast.
Yeah, if your gym has mirrors at right angles to each other than even better, can check things look good from the front and side. But agree its the side on view that will confirm if you're doing it right
Dont be scared of the DL - if you're benching and squatting then it should be straight forward and is a complimentary exercise. Just start light, watch yourself in the mirror, ask some to watch you/film you and go slow.