Clever, fashionable information notes (9)
I believe the answer is:
ingenious
'clever' is the definition.
(I know that clever can be written as ingenious)
'fashionable information notes' is the wordplay.
'fashionable' becomes 'in' (in can mean fashionable or trendy).
'information' becomes 'gen' (gen can informally mean information).
'notes' becomes 'ious' (I Owe You notes).
'in'+'gen'+'ious'='INGENIOUS'
(Other definitions for ingenious that I've seen before include "Displaying art" , "Resourceful" , "Creative" , "Clever, inventive" , "Brilliant" .)