Manner of making many points (4)
I believe the answer is:
mien
'manner' is the definition.
(mien can mean a manner or attitude)
'making many points' is the wordplay.
I cannot really understand how this works, but
'many' could be 'm' (Roman numeral for a thousand) and 'm' is present in the answer.
'points' could be 'en' (two compass points) and 'en' is present in the answer.
A single letter 'i' remains which might be clued in a way I don't understand.
This explanation may well be incorrect...
'of' is the link.
Can you help me to learn more?
(Other definitions for mien that I've seen before include "Bearing, demeanour" , "person's look" , "Personal bearing" , "Facial expression sounds miserly" , "A countenance like mine" .)