Have always found a good rule of thumb when tackling ballads is to listen to how the source singers did it; not to copy them, but to listen to how they made them work for themselves.
I would recommend a peep at some of the versions recorded in Ireland over the last forty years; there have been over 50 Child ballads recovered there (can provide a list if anybody's interested), many from the Travellers, thanks to their love of a good story.
The style of singing is very varied; John Reilly's 'stream of conciousness' approach, the simple storyteller's technique used by many of the Travellers, the highly ornament approach used by 'Little' Bill Cassidy, all individual, and all important to the understanding of the genre. If you can, listen to Martin MacDonough's beautiful rendition of Lady Margaret (Young Hunting); one of the most breathtaking renditions of a ballad I've ever heard.
Last year Tom Munnelly's 'Songs of the Irish Travellers' was re-issued, which includes Lady Margaret and Lamkin, and sometime next year the Goilín Club in Dublin is re-releasing Tom's and Hugh Shields 'Early Ballads in Ireland'; a double CDs worth from the North and the Republic - magic!
Jim Carroll