Adrian Furnham in Psychology Today:
There is an extensive literature in many disciplines on the topic of mate preferences and selection (Candolin, 2003; Prokosch, Coss, Scheib & Blozis, 2009; Shackelford, Schmitt & Buss, 2005; Schwarz & Hassenbrauck, 2012).
Much of the recent literature has been driven by debates on the power of the Body Mass Index (BMI) over Waist-to-Hip (WHR) ratios to attempt to determine the universality of male mate preferences (Dixson, Sagata, Linklater & Dixson, 2010). The debate has been won by the BMI school who argue from the data that it is the best and first-past-the-post choice factor when men look at women.
But there are a long list of other factors that play a part. They have one thing in common which is they are indicators of health and youth. Men like long shiny hair; they like a smooth skin. And they are very interested in symmetry.
More here.