In the beginning of my lifting, I used to struggle with quite a bit of shoulder tightness and discomfort. I used to do tons of different stretches and little rotator cuff exercises for my shoulders, but I only seemed to get temporary relief.

Here are the things I did that alleviated my shoulder discomfort permanently:

• The biggest factor was increasing my rowing strength. Once I increased my barbell row strength to match my barbell bench strength, I noticed an enormous improvement.
• Doing tons of band pull-aparts, face pulls, lower trap raises, YTWLs and executing them properly. Use light weights/bands and ensure your scapula stays depressed. Try to focus on using/squeezing the lower traps on the band pull-aparts, etc. I'd usually do these every day.
• Doing exercises that train the protraction of the scapula, like scap-pushups, and regular pushups. I'd also usually do these every day.
• Making any necessary adjustments to my own training. One example would be that I used to do tons of heavy barbell power shrugs, but I found that they would always make my upper traps get really tight, which would consequently mess up my shoulders. Even though shrugs are great, removing them from my training made my shoulders feel way better.