Symmetrical balance is most important, as long as you have some obvious muscle.
To attract attention shirtless is really great abs (on a symmetrical physique.)
To attract attention in a shirt is delts and traps.
To attract attention in shorts is calves and glutes (but you need some thighs too)
You’re right on. Wide shoulders, narrow waist, athletic hips. They call it the “X Frame” for dudes or the “Hourglass” for women.
Shoulders and glutes are usually a good place to start, but the most bang for the buck will come from training whatever is most lacking.
Hopefully you’ll train long enough to turn a “weakness” like small shoulders into a “strength” like big shoulders. Then you’ll turn your focus to the new “weakest” part. Like the chicken neck or skinny calves.