Foot covering isn't decorated (7)
I believe the answer is:
painted
'decorated' is the definition.
(I've seen this before)
'foot covering isn't' is the wordplay.
'foot' becomes 'pad' (padding is a kind of footing).
'covering' means one lot of letters goes inside another.
'isn't' becomes 'inte' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'pad' going around 'inte' is 'PAINTED'.
Can you help me to learn more?
(Other definitions for painted that I've seen before include "described" , "Pan diet (anag) - put on canvas" , "made up" , "Decorated" , "Coated with colour" .)