Depending on where you are coming from, you need to work out a point to start your cycling. If you live on the route - start from there! As I was coming from Glasgow, I took a couple of trains, and started my journey at the inland village of Ladybank. Refer to Scotrail for guidelines on taking your bike on their trains. (https://www.scotrail.co.uk/plan-your-journey/travel-connections/cycling)
Follow the National Cycle Network to the coast: I cycled from Ladybank generally following the National Cycle Network Route 1 (http://www.sustrans.org.uk/ncn/map) via Ceres to St Andrews. Enjoy the scenery on the route, and some freewheeling on a downhill into St Andrews.
St Andrews: With lots to see and do, St Andrews is a perfect place to stop and see some sights, and refuel on some food, coffee and cakes. I enjoyed a visit to the ‘British Golf Museum’, followed by a great late breakfast at its cafe which affords fantastic views overlooking the famous Old Course. (http://www.britishgolfmuseum.co.uk/)
Onto the East Neuk: There’s a little bit of a climb out of St Andrews to the south, and with some traffic around the town, cyclists should take care. I’d timed my cycling well to get a beautiful sunset as I cycled through the villages of Kingsbarns and Crail towards Anstruther, where I planned to stay for the night.
Anstruther is an ideal stop off point on the route, with lots of amenities including places to stay. If coming from the east it is definitely worth cutting off the main road down a few kilometres before the town, and then cycling through the historic streets of Cellardyke. I stayed at the excellent ‘Murray Library Hostel’ (http://murraylibraryhostel.com), enjoyed a fish supper at the famous ‘Anstruther Fish Bar’, and some live music at ‘The Boathouse’.