So many great suggestions for creating balance and a longer line:
V necks, scoop necks, sometimes boat necks,
Aubergine's draped neckline (like this one),
layering the crews and turtlenecks,
then the jackets, cardigans,
pendent necklaces in a V and scarves hanging straight.
Sometimes empire waists. Don't forget princess seams and fitted jackets.
Facing forward my bust is slightly wider than my chest line, and I look for more 'visual weight' in the shoulders to balance the bust (and hips).
In addition to all the tips to draw the eye up and down,
I look for clothes that draw the eye up and out to balance the shoulders.
Sometimes boatnecks with long sleeves, and
scarves & larger necklaces high on the chest (above the bust) work.
For short sleeves, the necklines above ONLY work for me WITH cap sleeves. Not sleeveless going straight up. Never sleeves cut straight across at the bust (tailer those). Never halter tops (two triangles wider at the bust unbalances narrow shoulders). Long, & 3/4 length sleeves are fine.
Aubergine's suggested draped neckline (like this one), works for me BECAUSE of the cap sleeves. There is a very similar one on the Nordstrom site with straight up/down wide strap that would not be nearly as good for me.
I would be wider at the bust and sleeve would not go straight down, but angle wider at the bust. The cap sleeves balance me.
Sleeves that flutter down also can minimize this side pop:
Google 'christina hendricks zack posen dress'. Note those sleeves also have height. For this effect without the front bust wow-pop of the Posen dress, I'll wear a close fitted camisole or T, with a sheer (sort-of-see-thru- sort-of-not) blouse. The cut of the blouse is important; seems to need to be close to the body with fluttery loose sleeves. I wear it out over (usually) black jeans.
A balconette bra pushes the bust forward but also narrows the bust along the side when facing forward ... reducing the side pop. It looks better under some clothes. (Can't stress a properly fitted bra enough).
A little puff (or shoulder pad?)to add height/width to the sleeve like on the Zack Posen dress can help balance.
Jackets with structure (maybe shoulder pads) widen & heighten the shoulders and create balance. I've considered experimenting with shoulder pads in everything.
Lapels on jackets - (Jackets not fitted to curves) - are just a problem for me. I have an Ann Taylor Loft 'open jacket' , no lapels that I wear open (to fit the bust). The one I have gives me extra height with a flipped up collar. Usually either an open jacket, a very deep V or very short V like they wore in the ??maybe 1940's, 1950's?? works well. Or a knit rather than fitted. No Channel type jackets with crew-type necklines. So sad.
A V-neck with an underlying camisole or modesty panel seems better on me. It's not just allowing a deeper V by hiding cleavage, but also seems better on shorter cut V-necks. Something about the layers adding depth to the outfit. Usually both tops are fairly neutral, in a darkness close to my skin color.
If I were forced to consider strapless for a dressy occasion, I would look for a heart shaped cut at the top, not straight across ( ... and for me a drapey, fluttery shawl and an amazing bra just for that dress ) Otherwise I would choose maybe a drapey top with cap/long sleeves or deep V-neck with maybe wide lapels and/or turned up collar with long to 3/4 sleeves or something else not sleeveless.
Sorry to get going on this. I do have trouble finding clothes that fit.
Oh, I follow Day Vies when she posts. I'm sure there are other classy posters on this site with similar challenges that I have not yet found. I miss a lot on this site. But I did find her and she is inspiring.