Encourage fashionable location, say (6)
I believe the answer is:
incite
'encourage' is the definition.
(I've seen this before)
'fashionable location say' is the wordplay.
'fashionable' becomes 'in' (similar in meaning).
'location' becomes 'site' (site is a kind of location).
'say' shows a homophone (sound like).
'site' sounds like 'cite'.
'in'+'cite'='INCITE'
(Other definitions for incite that I've seen before include "Provoke to action" , "Stir up (trouble)" , "Arouse to action" , "Stir up, hatred say" , "Urge (to violence)" .)