physical attractiveness would be more health, grooming, and self esteem based, from the non-binary people i know.
so i would say being healthy, groomed, and with good self-esteem in your presentation. the yardstick being your potential of the three. a person being less attractive if they refuse to try and be healthy, don't groom, and have low self esteem. low self-esteem leading to more frowning, crumpled posture, and wrinkles from stern faces. poor health including exercise, eating right, taking vitamin supplements. grooming including brushing hair, teeth, wearing deodorant, washing body, and wearing sun protection. more physically attractive if they have more of all three, up to their potential.