Ignoring the obvious requirements of a dinner date etc. and assuming basic standards of cleanliness and presentation, what do the ladies appreciate most in the dress and appearance of a man (be it client or boyfriend).

Sex in the city; a sharp suit and accessories,
Straight from the ranch; Jeans, boots and a t-shirt,
Straight from the gym: Sweats and a polo shirt.

Conversely what is a absolute turn-off for a first date or meeting.

Whatever is stylish, flattering, comfy, and ironed! And easy to remove! LOL

Wrinkles are a turn off (since you asked)!

As for cowboy boots..there's only two occasions I want to see cowboy boots:

riding a horse, or riding me!
(otherwise, leave 'em home)

....naked with a hint of aftershave

But if you insist on clothes then you never look better than when in shorts and a vest (though that's not ideal for a first date obviously!) x