I've bought several pieces from this jewelry store in Kensington Market. My best friend introduced me to this store and since then I've bought several pieces from them. They have ready to wear pieces and can also make custom pieces. Prior to my latest purchase, everything I bought was either ready to wear or a customization of a piece they already sell. They also create personalized tags on sterling silver or brass tags.
The prices are a bit high, but personally I'm okay with that if I'm buying local and can count on the quality of the material.
I recently had a rope ring made. It was too thin; it didn't retain its shape. Britt, the owner, had a new ring created that was thicker. I exchanged the initial ring for the new one, only paying the difference as the new piece was more expensive.
They also offer workshops, if that's something that you are interested in. Go check them out!