Anyone who does any kind of consistent pressing in their training can attest to this:
Sometimes your shoulders and pecs just feel horrible. Here is a quick soft tissue/capsule stretch to uncrap your junk.
#1- Choke a very strong band around something sturdy, loop the free end around your shoulder, place your hand (facing palm out) in the small of your back, and walk out until you feel like you are going to be forced into a sudden back flip. From here, move around, flex into the band, and just stretch every tight spot for at least two minutes. If you have any dysfunction going on in there, you will feel like wolves are trying to eat your arm off as soon as you walk some tension into the band.
#2- Now get a LAX ball, support the ball against a flat sturdy surface (preferably one you can get a lot of movement around, I am using my power rack in the below video) with the shoulder most portion of your chest (close to your shoulder but not on it). Find a spot that feels bad and move in every direction possible with every appendage possible, while holding the ball in place, for at least two minutes. This little pain ball adventure will not be enjoyable.
Once the time runs out, go back and do #1 again. There should be a huge improvement in both mobility and suicide inducing sensations of pain. Here is a video to demonstrate:
There is not greater joy in life than pain-free weight smashing.
Solum Per Exitum.