Good things to be put on penalty lines (6)
I believe the answer is:
finery
'good things' is the definition.
(fine items)
'put on penalty lines' is the wordplay.
'put on' is a charade indicator (letters next to each other) (some letters go on or after others).
'penalty' becomes 'fine' (a financial penalty).
'lines' becomes 'ry' (abbreviation for railway).
'fine'+'ry' is 'FINERY'.
'to be' is the link.
(Other definitions for finery that I've seen before include "Glad rags, best duds" , "Ostentatious clothing" , "Elaborate clothes and accessories" , "Fancy clothes or trappings" , "smart clothes" .)