slowhand
Head Pro
I would say that a putter fitting gives you a starting point. I had one and I was advised that I needed a putter with a lot of toe hang as I have quite a strong arc (although I couldn't see it myself). That meant I started looking at putters with small slants rather than plumber/flow necks, and found my Spider EX. Isn't as much hang as I was advised, but more than I had ever used before, and I'm happy with it.