Just my thoughts, but I think it can be a bit overwhelming for a girl to hear about your fetishes straight away. On the other hand, that may also have to do with the type of (dating) site you're on. Some sites, like for instance fetlife.com attract more kinky people. Although it's not really a dating platform, you may find a lot more open people there.

In general, I think, it has to do with how open minded someone is. Not having any experience with a long hair fetish doesn't mean that she could be open to it. I'm pretty sure that if you see a girl with beautiful long hair, she's someone who is proud of her long hair and enjoys to take care of it. I don't think she would mind if you were to take care of her hair for her (brush it, touch it, wash it). Things may also evolve from there to more fetish stuff.

All in all, the best thing you can do, I think at least, is to always be honest about who you are and what you like. Good luck with dating and oh, don't focus too much on getting everything right on the first couple of dates. Who cares, just meet some girls see how things go and slowly progress.