Walking tours are commonplace in the Netherlands, so you should bring the most comfortable pair of shoes you can find. Walking Tours of Amsterdam, the Red Light District, Photography Tours and tours of the historic Jordaan Quarter are available, according to Viator.com.
Weather can change quickly in the Netherlands, particularly in the spring and fall, so waterproof jacket, hat and shoes should be part of the contents of your suitcase. Pack a folding umbrella as well, so your sightseeing can continue even when it rains.
Bike Tours are commonplace in the Netherlands, and if you avail yourself of one of these tours you will need to be prepared with suitable active wear. Jeans are seen everywhere in Europe, and you should bring a light jacket and sweater to layer on and off as the need arises.
Your hair dryer should have a dual voltage switch to work with 110 and Europe's 220 electricity. You will also need a three-prong adaptor plug to accommodate the European electrical system, according to Emerson College's list for the Netherlands.
If you wear contact lenses, you should pack enough lens solution for your trip, as it is difficult to find in Europe. If you wear glasses, it's a good idea to bring an extra pair.
If you intend to attend cultural or special events in the Netherlands, bring a good dress and pashmina shawl to cover your shoulder. Men should bring good slacks and a white shirt and tie.
Bring a number of pieces that go together so that you can easily mix and match them. Bring more tops than pants to freshen up as needed.
Because of the frequent wet weather, you should bring extra socks so you can change them when they become wet. This will make you comfortable quickly after a drenching.
It's a good idea to bring a travel clock to help you stay on schedule for early morning events. Bring extra batteries so that you don't have to spend time looking for a place that sells batteries.
Of course, you will want to take many photos of your trip to the Netherlands, so bring your camera and extra batteries. Keeping the camera in a waterproof case is a good idea because of the Netherlands' sudden rains.
Slip a small backpack or day pack into your suitcase so you will have a smaller bag to carry necessary items during your sightseeing excursions. This will make it easier to carry clothing items to layer, rain gear, sightseeing books, camera and other items.