Most of the clothing I own is thrifted, but whenever I go to Ottawa, I always visit Aritzia. It's lucky the store doesn't exist in Montreal as it is quite expensive (by comparison to my thrifted items!) and that most of what they sell is quite interesting in design and fabric. It is one of the rare stores that always carry all-wool sweaters during the winter as well as very soft and durable flannel shirts (I have been buying one every year since I got my first job). Also, their website and lookbook are very inspiring as they offer unexpected combinations and layerings; their silk and cashmere vintage-ish pieces always make me want to run to the closest charity shop to shamelessly copy their newest looks!
All pictures from the Aritzia blog.