The hourglass figure to start (though I like bigger women). The ratio of 7 to 10 based on the midsection of the woman compared to her hips. It's easier for the male to spot a female if she has an hourglass figure. The smaller the ratio (5 to 10) even though it isn't found in nature, the more attractive the typical guy would rate her.
Symmetry has a lot to do with attractiveness as well. She has a higher pitched voice showing elevated estrogen levels. Her skin has a shine to it and appears smoother. She may even have a scent when she's ovulating that the guy might not know he's picking up.
Guys tend to gravitate to the chest of a woman. This is instinctive and shows the male that the woman has reached puberty. The size of the breasts might be related to how breast feeding children or something much like the idea that wide hips make for easy (or easier) childbirth.
I'm a sucker for colored eyes like blue in particular. Though I don't necessarily rule out any other eye color as a deal breaker.
Guys are more drawn to the germanic or russian faces of women. They love thicker women so chubby to curvy women with less of an hourglass figure. Ample natural breasts (I swear I was a bottle baby growing up), and a nice ass (size 12-18 US). Lips are soft and medium to full. That's about it physically, there is more beyond that I look for.