I personally don't really experience shoulder dysphoria. Everyone's got different things about their bodies they dislike, very much including cis people—one of the important moments of transition is recognizing that you've moved from having body image issues for trans reasons to having body image issues for normal societal reasons.
One tip I've heard from friends that has helped with shoulder dysphoria in particular is, paradoxically, to work out. Trans women I know who lift weights say that they start to love the breadth of their shoulders because it makes them look powerful and it's something they've taken ownership of. It may also be worth looking up pictures of buff women just to remind yourself of the range of shapes that bodies can have and the ways people can make any shape look great on them.
(As an aside, if you send me advice asks like this, make sure to check back in on the comments periodically! People are leaving a bunch of good thoughts there from a much broader perspective than I can provide on my own.)



