I know exactly what you do because I was both a Principal and an Assistant at the HS level for 22 years.
I wore a suit or Sportcoat/Slacks four days a week, and usually Dockers and a School Polo or sweater on Fridays.
I found Four options: Florsheim Comforttech, Bostonian has an equivalent that is excellent, Rockport and Sketchers has a couple of styles of dressy loafers that look good with suits and can be used for casual uses as well.
I wore a suit or Sportcoat/Slacks four days a week, and usually Dockers and a School Polo or sweater on Fridays.
I found Four options: Florsheim Comforttech, Bostonian has an equivalent that is excellent, Rockport and Sketchers has a couple of styles of dressy loafers that look good with suits and can be used for casual uses as well.