When I lived in Panama there was a woman down the street from my house who would make anything - just from a drawing. I designed a couple of items and she made them come to life! It's a little hard to speak to quality and fit, as I was quite young and not very discriminating. But I was happy with the outcome because they were things that I had in my head that I wanted to wear. The one that I remember most was a white top made of some kind of silky fabric (I probably had no idea what it was even then). It had these flowy full sleeves that ended in tight, wide cuffs that I had crocheted with tiny pearl-like beads interwoven, and a long row of pearl buttons down the front. I'm sure I wouldn't be caught dead in it now, but I felt fabulous in it when I was 19.
On a funnier note, I also decided to try to design and create a dress all by myself as a teenager. I didn't have access to a sewing machine and had more hours of boredom than I knew what to do with! Sleeves were outside of my comfort zone, and zippers and buttons were a no-go, so I ended up with a hand sewn, drop waisted, wide collared dress that I could barely get on. I managed to squirm and shimmy my way into it! Not my finest hour, but I did kill some time.
Anyway... All that to say, there are people out there who can do it, but they are probably hard to find!