Fashion, because I live in a huge tourist town. I see bra less sixty year old women, people walking through the grocery store in dripping wet bathing suits, man capri pants, and grown adults wearing cartoon characters on there clothing from head to toe on almost a daily basis.
Appearances can be deceiving so judging by appearance is a bad practice however if I had to choose between the 3, Fashion or manner of dress would be my choice. since clothing says so many things about a person. is it clean or dirty, professional or casual, tight or loose, bold and bright or bland and dull, coordinated or mismatched, trendy or conservative, wrinkled or ironed, inexpensive or extravagant etc...
The first thing I always do is look somebody straight in the eyes to see if they look comfortable talking to me. So, i choose face. I always look at a persons face first.