This writer rejected employer's raise in relief (6)
I believe the answer is:
Here is my best explanation:
'raise in relief' is the definition.
(I've seen this before)
'this writer rejected employer's' is the subsidiary indication.
'this writer' becomes 'me' (the person who is writing these clues**).
'rejected' is a reversal indicator.
'employer's' becomes 'boss' (boss is a kind of employer).
'me' in reverse letter order is 'em'.
(Other definitions for emboss that I've seen before include "printing style", "Execute in relief", "In relief", "Ornament in relief", "opposite of grave", "raise some relief", "Raise (a design) in relief", "Provide relief", "Chase" and "Ornament with slightly raised pattern".)