Men's shirts should be coordinated, open-collared, light in colour and either plain or with a very small pattern. Pants for both men and women should be dressy - that means no denims, cottons or cords. Do fine-tune the details. Absolutely nothing you are wearing should be wrinkled, frayed or sloppy. Don't even consider athletic shoes or sports attire, which may send the message that you'd rather be on the playing field than doing business.
Men can shed the tie and switch to open collars or knitted tops with dress pants.
They can keep a neutral sports jacket and a matching shirt and tie on hand for unexpected schedule changes. And do remember the importance of accessories. Don't get overwhelmed. Buy, and get advice, from a reputable retailer who will sell you quality and fit, not just a name brand. Your clothing adviser should listen to you and understand your needs, and dress you accordingly.