Artefact that's frightfully nice art? Nothing in it! (8)
I believe the answer is:
creation
'artefact' is the definition.
(creation is a kind of artefact)
'frightfully nice art? nothing in it' is the wordplay.
'frightfully' is an anagram indicator (I've seen this in other clues).
'nothing' becomes 'o' (looks like zero - 0).
'in it' means one lot of letters goes inside another.
'nice'+'art'='niceart'
'niceart' with letters rearranged gives 'creatin'.
'creatin' going around 'o' is 'CREATION'.
'that's' acts as a link.
(Other definitions for creation that I've seen before include "Haydn oratorio" , "Life, the universe and everything" , "Act of bringing into being" , "Act of God" , "Process of generation" .)