Building a big, round shoulders won't be an easy task, and you have to focus on all three heads of shoulder muscle. Anterior deltoid is engaged in almost all chest exercises and it is front head of shoulder muscle that is mostly overtrained. Lifters often don't pay attention to their medial and posterior deltoid, that is very bad for muscles balance and proportion. Training only with exercises that build a front head of shoulder will lead to bad body posture and shoulder injuries.  Medial deltoid is very important for building shoulder width and Posterior deltoid is important for body posture and building it is greatly improving your body look from the back. That means, to look bigger and broader you have to train every side of shoulder muscle equally.   To build big shoulders you have to use compound and heavy exercises with some additional isolation exercises. So train with heavy weights (about 80% of 1RM) and with rep range from 8 - 12 which ...