Broomfield Hill springs to mind instantly
Maid on the Shore is a fairly obvious one
The use of witchcraft, particularly by disapproving mothers to get rid of unwanted suitors for their sons include Clyde's Water and Lord Gregory
A superb example of the use of the accusation of witchcraft to break up an unwanted liason is to be found in the beautiful 'Andrew Lammie'   
Tam Lin, of course - a woman who fights to free her lover from the otherworld
The Two Magicians
The use of witchcraft in ballads and songs is not immediately obvious
For ballad references, Lowrie C Wimberly's 'Folklore in the English and Scottish Ballads is a superb reference.
Enjoy your search Harry - it's good fun
Jim Carroll