Clue: Elaborate on line in bill, leading man to appeal (6,3,5)
Answer: TICKLE THE FANCY
Explanation: Definition: app
A charade of TICKLETHE, an envelope ('in') of L ('line') in TICKET ('bill') plus HE ('man'); plus FANCY ('elaborate'). 'Leading' seems to be required by neither surface nor wordplay, but does no harm. 'On' is required, to indicate the order of the particles.