Stick with a solid colour shirt, as stripes can be distracting. White is always safe. French blue or lighter blue is also safe. I like the blue shirt with contrasting white collar and cuffs because it gives you the bright spots of a white shirt with some colour in the field. For the tie, avoid paisley, unless you are in the 1980s-early 90s. Solid colours with small patterns are usually the best, like black with white pindots, burgundy with yellow or pink, or whatever. I also like ties with patterns woven into them as opposed to smooth ones with prints. Avoid red ties with white shirts and dark suits as you will look cliche. Black works with navy, and most dark colours work too, but don't wear blue with blue with blue, unless you are Regis Philbin or Ace Rothstein (from Casino). Also, wear a plain white handkerchief with just the points showing in your breast pocket. It's an easy touch most people forget and it shows you are a conscientious dresser and pay attention to details.