When coming to the Netherlands, be flexible: pack an umbrella (or two—the topography results in a blustery wind, which makes short work of a lightweight frame); bring a raincoat (with a thick liner in winter); and always have a sweater or jacket handy. For daytime wear and casual evenings, turtlenecks and thicker shirts are ideal for winter, under a sweater. Unpredictable summer weather means that a long-sleeved cotton shirt and jacket could be perfect one day, whereas the next, a T-shirt is as much as you need. Layers are always a good idea.
Essentially, laid-back is the norm. Stylewise, anything goes. Men aren't required to wear ties or jackets, except in some smarter hotels and exclusive restaurants; jeans are very popular and worn out in the evenings. Cobblestone streets make walking in high heels perilous—you don't want a wrenched ankle.