Increase production of headless puppets! (4,2)
I believe the answer is:
step up
'increase' is the definition.
(synonyms)
'production of headless puppets' is the wordplay.
'production of' indicates an anagram.
'headless' means to remove the first letter.
'puppets' with its initial letter taken off is 'uppets'.
'uppets' anagrammed gives 'STEP-UP'.
(Other definitions for step up that I've seen before include "To be promoted" , "Increase as with pace - or ascend stair?" , "Approach" , "Advancement (on a ladder or career)" , "Come forward" .)