Fashionable figures the writer's detailed (9)
I believe the answer is:
intensive
'detailed' is the definition.
Both the definition and answer are adjectives. Perhaps there's an association between them I don't understand?
'fashionable figures the writer's' is the wordplay.
'fashionable' becomes 'in' (in can mean fashionable or trendy).
'figures' becomes 'tens' (ten is a number).
'the writer's' becomes 'I've' ('I have' can refer to the person writing).
'in'+'tens'+'ive'='INTENSIVE'
Can you help me to learn more?
(Other definitions for intensive that I've seen before include "Demanding" , "Very vigorous or thorough; concentrating" , "Concentrated" .)