Stephen,
While I agree that it is much harder to 'back track' if you've made a poor first impression, I also like to remind students that even if they didn't do their best, with the right guidance, there is often still the possibility for a second chance. I'm glad to hear that you have a place to send students for interview clothing. I offer recommendations through other courses I teach because it is so critical to look professional but of course not everyone has the money to spend on professional looking clothes.
Elizabeth Kemler