What clothes designers may be good at in current environment? (12)
I believe the answer is:
trendsetting
'what clothes designers may be good at' is the definition.
(designers may set fashion trends)
'current environment?' is the wordplay.
'current' becomes 'trend' (current can mean a trend or movement).
'environment?' becomes 'setting' (setting is a kind of environment).
'trend'+'setting'='TRENDSETTING'
'in' is the link.
(Other definitions for trendsetting that I've seen before include "creating new fashion" , "Sparking something new and fashionable" , "Leading fashion" .)