You want to make sure you wear the right uniform. Make the effort to look nice for your date. Choose your attire carefully and make sure it's not ripped, stained or missing buttons -- including your socks and underwear. Always wear a clean undershirt because it absorbs sweat and odor, keeping it away from both your body and your outer shirt. Wear socks to absorb foot sweat and prevent odor-causing bacteria. If you have problems with foot odor, consider putting powder or absorbent inserts in your shoes to combat it.
Also, be sure to dress properly for the weather and occasion. Nothing's more embarrassing than shivering in front of your date or being turned away from a club because you're wearing tennis shoes.