Its almost impossible to do justice to this subject. We tackled Switzerland with a 4 day Swiss travle pass and where very happy with our choice. We would always combine train with boat travel on each day (all included in price) and that worked out very well. Switzerland is not cheap and hence the first steps to take are as follows:
Get a Simcard for Swiss data to book hotels and to download travel apps. Don't for get to buy a Swiss power point adapter with the latest flat (diamond) shape to charge your phone. You will always find power points in trains but not all of them accept the older style round travel adapters.
Now its time to type in any destinations you fancy and look up your itinerary on a Swiss rail travel app. The Lakes and the Matterhorn are too good to miss. There is and Italian and a French South (warmer climate) and the cooler German North. All three sections are a must see. For the Matterhorn we chose the afternoon, which allowed us to make the high altitude ascent for just 25% of the regular fare.