Same problem, my bust is my largest measurement and I've no shoulders to speak of. A figure often mocked by brand dresses, I agree.
I find I do best in long sleeve blouses with modest embellishments kept close to the neck, (draws the eye closer to the face--even works on men.
lol )
And
always corseted in the back, your waist is your best friend as I'm sure you're aware.
Paired with a skirt with a generous waistband, custom fitted or with waist ties and preferably a-line.
I'd skip most JSKs, but sleeveless ones are good as long as they don't sit too high on the breast.
If you want an OP then there are a few classical gems that can flatter a busty figure, but skirts and blouses are the best staple.
Example.
Ideal figure, low neck (breaks up the bust, if the neck were arm-pit level it'd make you look bigger) waist-defining belt, long puffy sleeves, a-line-
Of course, this all goes out the window if you're a sweet lolita...
sweatdrop