For ladies: Very clean blue jeans, either hip hugging or secured with a black leather belt with a shiny buckle. Black leather shoes with heels. Lacy or diaphanously silky top that reveals the shoulders. Options here are spaghetti strap, tube top, off one shoulder (Flashdance look), etc. Shoulder length hair in some type of ponytail.
These rules are very strict. Out of maybe fifty dating couples I saw tonight, only five or six people total weren't wearing this exact uniform.