Thought I'd throw open my current state of travel planning for our, my wife and I, upcoming mostly Switzerland trip, from late August into September. Right now leaning toward half fare cards instead of flexpass.
First four nights Luzerne. I loved the area on a quick visit 33 years ago and it was my grandmother's favorite part of Europe. A nice way to start the trip. Thinking of a boat trip for sure, just not sure on length. The Vierwaldstattersee is an amazing lake. Also, go up one of the mountains, either Rigi or Pilatus, if Rigi maybe in coordination with boat trip. For Luzern itself want to spend some time just wandering around, checking out architecture, the Lions monument and the Bourbaki panorama. It will be three full days in Luzern area.
Next six nights Wengen/Murren/Lauterbrunnen area. The snobbish side of me says to not spend so much time here as its such a Rick Steves emphasized area and my holier than thou attitude kicks in that I don't just want to follow the crowds. But then I start looking at photos of the area, and it looks like such a beautiful area with so much to see that in this instance, count me in. I know my wife and I will both really enjoy the area, based on our US travel likes. Planning some walks/moderate hiking, day trip to Brienzersee. and following Ricks recommended walking tour of Interlaken to see some of those old grand hotels.
Not sure about the Jungfraujoch experience because of crowds and costs. I do find that crowds take a significant amount of enjoyment of sightseeing type experiences away, so will have to weigh this issue.
After that, probable 3 nights in Lac Leman area. We would take the regular trains along the Golden Pass route to get there. My mother has a good friend who lives in Geneva, we'd want to spend some time with her, probably visit Lausanne and Montreux.
From there we would do a little geographic backtracking and go to Freiburg in Germany to visit the town where I studied for a semester all those many years ago. Perhaps four nights in the area, with day trips to the Black Forest and Baden Baden. My 19th century architecture interests are stirred up by Baden Baden. Still thinking about going as far north as Heidelberg, maybe, in which case get a Freiburg to Heidelberg IC ticket with 6 hours or so stopover in Baden Baden.
This is as far as I've gotten so far, for the last few nights thinking about getting back to Switzerland via Lake Constance and visiting St Gallen, and have our last two nights in Zurich.
In this scenario we are not seeing some of the iconic Swiss heavy hitters, like the Glacier express or Zermatt, but this does offer a pretty good balance of experiences. Still pondering about adding Ticino area as well, and of course trying to resist the ever present danger of trip over expansion.