Employees are your most valuable assets. They are the heart and guts of a company. This doesn't mean that from time to time, you aren't going to do what is good for the company.
As tempting as it seems to wear tennis shoes with your tux, don't do it. I think it looks ridiculous. If you're 14 years old, maybe give it a shot. In general, don't portray anything that says 'I'm too cool and I don't care.'