Articles requiring skill, basically (2,5)
I believe the answer is:
at heart
'basically' is the definition.
(both can mean fundamentally or deep down)
'articles requiring skill' is the wordplay.
'articles' becomes 'a the' ('a' and 'the', indefinite and definite articles).
'requiring' means one lot of letters go next to another.
'skill' becomes 'art' (both can mean a talent).
'athe'+'art'='AT HEART'
(Other definitions for at heart that I've seen before include "Substantially" , "In one's innermost feelings, in that era" , "Really" , "real character" , "Basically" .)