This
I was told, a few months after starting a job 25 years ago, clean/polished shoes sealed the deal. . . . I agree, and it's that attention to a relatively minor, but important detail that does it for me.
If you're good enough to work in a supermarket, you're better than any of the leaders we've had in the last 15 years . . . I digress, Trousers and shirt, ironed, and proper shoes . . . Ie leather, clean/polished will put you in the sweet spot IMO.