If you are not an experienced Swiss hiker, I would take the train from Geneva to Aigle and the bus to Villars. There are a number of hotels you can stay at your first night, maybe the Alpert Fleuri? Anyway, from there walk up to Bretaye (3 -4 hours) where you'll find lodging, and then you should walk around the back and come back around the back side (maybe 25km). The local maps are good and easy to read and give you the details for any length and difficulty of walk you could desire. It also includes magnificent views of the Alps across the valley. Good luck. over 6 years ago
Three day train pass. Gives you freedom to explore at a cheaper rate around the lake and outwards. Purchase this pass at main train station. Lovely towns around the lake.
Also, buses can take you comfortably to Annecy in the French side. Gorgeous medieval town on an alpine lake. About 30 minutes on a direct bus from geneva bus stop. Great day trip! about 6 years ago