Writer should avoid slim-fitting garment (6,5)

'slim-fitting garment' is the definition.
I don't know anything about this answer so I cannot judge whether this works.

'writer should avoid' is the wordplay.
I cannot quite see how this works, but
'writer' could be 'pencil' (something which writes) and 'pencil' is located in the answer.
'avoid' could be 'skirt' (skirt can mean to go around or avoid) and 'skirt' is found within the answer.
No letters remain.
This explanation may well be incorrect...

Can you help me to learn more?