It's not always just pecs and anterior delts. It could also be tightness of the lats. When you stand in a relaxed posture do your hands face backwards? cause of tight lats. I do many things to stretch out my chest and work on my shoulders. You may be stretching out knots which doesn't work... Try to foam roll your lats and chest and then stretch after foam rolling.
I use this stretch everyday and has helped out a lot.
I try to keep my head, thorasic region, butt, and heels on the wall and bring my arms into a W. Then extending the whole way up trying to keep the back of my hands on the wall along with my elbows and posterior delts.
This guy does it pretty much perfectly.
I couldn't find self myofacial release on the chest but same concept. Remember, foam roll THEN static stretch. Good luck bro.
i do the W's and L's standing with kettlebells on my back and posterior delt days. It's for scapular protraction, for me at least, which tends to come along with the rounded shoulders and tight chest.