Best clothes in tatters after having left to wander around (4,4)
I believe the answer is:
glad rags
'best clothes' is the definition.
(I've seen this before)
'tatters after having left to wander around' is the wordplay.
'tatters' becomes 'rags' ('rag' can be a synonym of 'tatter').
'after having' is a charade indicator (letters next to each other).
'left' becomes 'l' (common abbreviation).
'to wander' becomes 'gad' (gadding is a kind of wandering).
'around' indicates putting letters inside.
'l' placed into 'gad' is 'glad'.
'rags' put after 'glad' is 'GLAD RAGS'.
'in' is the link.
(Other definitions for glad rags that I've seen before include "Smart clothes (for a special occasion)" , "What partygoers showed up in" , "Special kit" , "Best bib and tucker" , "best suit" .)