Itinerary help with day trip from Haarlem

If seeing beds of all-coloured tulips and hyacinths as well as lots of other bulbs, and being able to walk the paths between the beds which are done in all sorts of artistic shapes sounds like a must to you then go. If it doesn't and Amsterdam does, do that...

No reason as far as I'm concerned for taxis based on what you want to do. The trains are excellent, fast and very frequent; the linked trams do the last mile in style.

I'm 70 and just thinking of older. If you feel older you may need taxis. I wouldn't say not.

But give the trains and trams a chance. The OV Chipkaart means that one pre-loaded contactless card buys all your trams, buses and trains with no physical tickets. So easy.

Yes, Keukenhof is a must see! I rank it up there among my best travel highlights along with cherry blossoms in Japan and fall leaves in Vermont!! I am surprised that you would consider skipping the tulip fields. You could hire a driver to take you to see them outside of Keukenhof I imagine to get away from some of the crowds. . We timed our trip to The Netherlands for the blooming of the tulip fields.
Skip Maurodam; there are better things to see and do in The Hague. like Panorama Mesdag.
Go the The Hague and Delft. Both beautiful, one a town, the other a small city, where the Dutch Parliament is located. The small and excellent. Mauritshaus Museum is located in The Hague and is home the royals’ collections. Wonderful. “The Girl in the Pearl Earring” and other treasures by Vermeer are in this museum.
If you have time, Leiden is a beautiful canal laced small city with a famous university. It is where The Pilgrims lived for ten years after fleeing England, before leaving for the New World.
You take the train to all of them, very easy.

I’m surprised no one has mentioned yet that your visit coincides with our national holiday Kingsday on April 27. The whole country will turn orange and if COVID doesn’t spoil things again, cities like Amsterdam will be packed with people celebrating Kingsday. To get some idea of what to expect, see https://www.holland.com/global/tourism/information/general/the-royal-family/the-origins-of-kings-day.htm and https://www.iamsterdam.com/en/see-and-do/whats-on/major-events-and-celebrations/kings-day

If you want to escape the Kingsday crowds in the cities, a visit to the Keukenhof is a good idea.

Wow! Thanks for the heads up about Kings Day- definitely don’t want festival crowds! Will have to consider the options. Oregon and Washington known for tulip fields so only interested in Keukenhof because it looks like a well planned garden, which we do enjoy.

‘Older’ as in later 60’s. Seasoned travelers. Definitely able to walk distance and work with trains and trams.

Madurodam just looks quirky and fun. We have 4 weeks following in France too so will be seeing plenty of museums and architecture.

We flew into AMS on King's Day and took the bus straight to Haarlem, where a massive celebration was going on (2018), lots of fun to watch and get caught up in the spirit. Lots of street noise that ended promptly at 10:00 as we were going to bed. The only downside was that the big central square was full of carnival ride equipment and empty food stands for days after, detracting from its charm.

We went to Keukenhof shortly after, enjoyed it up to a point. It was less crowded early than later. I haven't been to the Skagit tulip scene here but I expect Keukenhof is a lot more compact and visitor-friendly. They've been in the tulip business a lot longer. And there are interesting exhibits about tulip history, the 17th-century investment bubble, etc. But Nigel's point is still valid -- depends on what interests you most in your limited time. We'd been to Amsterdam before so had been to the "highlights," the tulips were a spring bonus on this trip.

Oregon and Washington known for tulip fields

with windmills?

Hello Andrea from Portland! We will be staying in Haarlem during the same time, the last week of April.

Interesting strategy to go to Keukenhof on Kings Day. I think I’ll consider that. Large crowds right now aren’t my thing.

You are not going to avoid crowds, not even in Haarlem. Keukenhof has evergreens and perennials, as well as plenty of bulbs. It is a must-do. Crowds might be less in Amersfoort. Neither Leiden or Utrecht can be exhausted in one day. High-mileage walkers can do both those cities without waiting for busses. Some interesting places, like museum of musical automata have always had timed tickets for tour-only visits, which sell out.

With the Mauritshuis and the larger Kunstmuseum, I'd skip Madurodam. But it's a matter of preference.