We try to make them aware that EVERYTHING affects your image and your performance. Getting something EXACTLY right and getting something SORT OF right are not the same thing. Imagine flying on an airliner where the pilot safely lands "most of the time"... would you sign up for a ticket?
As picky as it might seem, we talked about how to wear the concert attire on numerous occasions during the Fall semester. Specifically, we addressed shoes and socks. For the gentlemen, we said several times over 4 months: "full length black dress socks...no anklets or footies."