Cousins tiling houses impress (6)
I believe the answer is:
instil
'impress' is the definition.
(I've seen this before)
'cousins tiling houses' is the wordplay.
'houses' says the answer is hidden in the clue (part of the clue houses the answer).
'INSTIL' can be found hidden inside 'cousins tiling'.
(Other definitions for instil that I've seen before include "Inject ideas into mind" , "Introduce gradually into person's mind" , "Gradually establish something in a person's mind" , "Put in drop by drop" , "Drill" .)