Yep, I'm a prof, in the SW, and almost as old as Old Man NOBD. The suggestions so far have been very good. Mine are:
For shoes, penny loafers. I love Alden's leisure hand sewn model. I used to hate penny loafers, but now I'd be happy with just them and boots.
Pants: khaki chinos and light and/or mid gray wool, ideally with 1.75-2" wide cuffs. I wear jeans sometimes too, blue or gray.
Shirts: Agreed on university stripes and gingham. I also suggest some...