Fashionable points, retaining rule, making leaders (9)

'leaders' is the definition.
I know nothing about this answer so I can't judge whether this works.

'fashionable points retaining rule' is the wordplay.
'fashionable' becomes 'in' (in can mean fashionable or trendy).
'points' becomes 'spires' (I can't justify this - if you can you should believe this answer much more).
'retaining' indicates putting letters inside (inserted letters are held or retained).
'rule' becomes 'r' (abbreviation for rule).
'spires' enclosing 'r' is 'spirers'.
'in'+'spirers'='INSPIRERS'

'making' acts as a link.

Can you help me to learn more?