After you have self-assessed your bench press and you have determined that you are unable to get in the correct position, you need to work on your mobility for the movement.
The common fault in bench press is usually the lack of shoulder extension without a compensation. If there is a restriction, there are a few common treatment for this:
Band with internal rotation and extension – using a band, place it around your elbow. Put your hand behind your back. Start to rotate in the opposite direction of the band. Grab your other hand and roll the shoulder back so that it’s in a good position. Lean into the stretch. You will feel this in your pec and in your arm pits. Hold minute one to two minutes.
Quadraped T-Spine Rotation – if there is an upper back poor movement pattern this is a good solution to treating your mobility. On hands and knees, place hand at the junction of your upper head and neck. Think about rotating with your elbow towards the ceiling. Actively engage your middle trap and back of the shoulder to move the upper back and ribs. Complete for reps to increase the range of motion.