So from a guys point of view bum or boobs or something else?
For the ladies....what do you look at?
And for the record I'm a bum man, it doesn't have to be cute and pert etc (chance would be a fine thing!) but just shapely in a nice way.
From afar, I'm a legs man. But only because it leads to what I notice at medium-distance: posture. More specifically: the jawline, neck, all the way to the shoulders are turn ons for me.
Then close distance. The eyes. I like catching pupils dilate. Nothing else matters about her if I notice that she's "into me".
The windows to the soul are always my starting point.
I look for uniqueness that someone owns solely to themselves.
Eyes, and smile. I like to check out hair, but, as I get older am not so hung up on that as the younger me was. Longer hair still does catch my eye, silver hair is nice, and none is fine, too. Beards and mustaches interest me quite a bit.
Beyond that, general build and how a guy carries himself can draw me in. It's largely about projection of persona: quiet confidence, a sense of fun or even mischief, and intense curiosity can be a fascinating combo together or separately.