#2: Amersham to Chorleywood
Walking from Amersham station to Chorleywood makes sense for lots of reasons above and beyond the great walks available. With four trains an hour and using the Oyster card, getting to Amersham is cheap and easy. Getting home from Chalfont & Latimer is even easier - there are usually six trains an hour (with the addition of the two trains per hour from the Chesham branch heading back to London) - so it is sensible to do the walk in this direction.
There are several ways of walking between these two stations, you could head south and down into the Misbourne Valley to Chalfont St Giles and then back up past the Chiltern Open Air Museum. My recommendation, however, is to head north-east out of Amersham station to the Chess Valley towards Latimer and Chenies. Although it takes a bit of time to get out of suburban Amersham, once you have, you can do an easy walk (c 10km, no hills!) giving beautiful views of the valley.
Find out more about walking from Amersham station.