After bench pressing seriously for a few months, I notice that one side the shoulders is a lot more developed, and the other side, the chest. Searching up about why should activation occurs more, I find it that it is due to the line of the barbell not being underneath line along nips when viewed from top down.
So, I theorize that the barbell, from top down view is not perfectly horizontal, but rather tilted. What could be some cues to have it be more horizontal?