Depends what you want.
Beaches - Kingsbarns(amazing beach, very dog friendly and fairly well enclosed)
Lower Largo/Shell Bay(depending what end you start at...another fantastic doggy beach, lots of open space and is a good 8 miles or so long)
Tentsmuir(Probably the biggest beach in Fife, has an amazing forest too with tons of paths, you could spend days there!!!)
Foresty bits - Tenstmuir
Keils Den(quite small but a lovely place to visit)
Other general walks
Loch Leven, it's a nature reserve so dogs must be onlead but it's a lovely place.
The Lomond hills, great views, might encounter sheep
Lochore Meadows, very dog friendly, lots of woods/parkland/water etc
The Fife coastal path, my favourite stretch is Elie to Pittenweem, lots of different terrains and the views are spectacular
