Is your friend a Canadian resident traveling aboard? Or a Canadian returning to Canada? If so, then declare them as "Canadian Personal Effects return to Canada". Your friend will need the form Form E24 - Personal Exemption CBSA Declaration, or B4 - Personal Effects Accounting Document respectively.
If your friend is a foreigner, and you are the receiver, then if the value of the clothes is under $60 CAD, you can declare them as "UNSOLICITED GIFT" and Canada admits duty-free gifts up to $60CDN in value.
Use your friend's "Personal Name" as sender, and do not use a business name as sender otherwise the gift exemption won't be applicable.