Very much a work-in-progress, we are planning a tour, possibly a fortnight long, using our wonderful Thorn tandem. At the moment I'm looking at going out on 5th August, and returning on 19th. The first thing to decide, in my view, is how we get there. I had expected that Eurostar, all the way to Amsterdam, would be cheaper than the ferry, but it would appear not. Firstly, the direct trains from London leave at very inconvenient times: two of them are too early in the day to be of much use - leaving on the 11.04 from St. P would mean trying to take a bike on a train to Lpoo St at a time when such things are banned by Later Angrier. The preferred, train, leaving at 12.58, is £125 per person to get out there, and £51.50 each to return. Add to that £30 each way for each bike (can't take tandems on Eurostar), as well as fares to and from London (OK, we would need to buy tickets to Harwich as well), and that becomes expensive - considerably more so than the ferry. So it seems that the ferry, at £330 return, takes out a load of stress and when we get there, we just start cycling.
We want to combine cycling with culcher and sight-seeing, so some days we might spend a couple (or more) of nights in a city, Otherwise, we would probably want to cover about 40 miles a day when cycling. At the moment, places I'd like to see are Utrecht (we've been there once before, but only to catch a train, never stayed), Delft, Maastricht, the Frisian lakes plus of course other places recommended by the YACF travel-writers' association...