A trip to Kurashiki is much more enjoyable when you are able to visit the various museums and historical sites however, be aware that most of the museums in the city are closed on Mondays.
If you decide to visit Kurashiki on a Monday, you will be to walk in the Bikan area, visit Achi Shrine, and browse through the various shops, but most of the famous attractions (Ohashi House, Ohara Museum of Art, Rural Toy Museum, etc.) are closed on Mondays, so if you plan to go to any of these places, make sure to avoid Monday. The one positive side is that because so many things are closed, Mondays are relatively tourist-free. For those who do not plan to go to the museums, you may actually want to visit on a Monday. Either way, the closing days are a good thing to keep in mind!
For those planning a trip to Kurashiki, do NOT put Tivoli Park on your itinerary.
This is not because the park is boring, it is because as of January 1, 2009 Tivoli Park is officially CLOSED. If you travel to Kurashiki for the purpose of visiting this park, you will be greatly disappointed!
Kurashiki has many great historic sights and museums, so there is no reason to cancel a trip to the city, but be aware that Tivoli Park is closed indefinitely.