"I think the sort of misunderstanding I've had problems with is not so much someone making advances to me, " no thanks, I'm asexual" works fine, but it is a problem when other people think I fancy them, it can ruin a friendship, and " no really, I AM asexual, HONEST" is often taken with some sceptisism. The worst is long standing female friends, who start to wonder if, because I have never indicated an interest in men, there is a likelihood I may be interested in them. This is hard, if they start to back off, but even harder if the start to signal that they may be open to a bit of experimentation! I just wonder if wearing the black ring means everything is up front and straight forward from the start"
OP: That doesn't say very much about your long-standing female friends does it? That's sad for you actually. If they're long-standing, then they should understand. I don't think that wearing a ring will cure/help to be honest, the people you're aiming at should have got the message a long time ago.
I've been around long enough now to realise that sometimes there's nothing you can do to persuade/educate people if they're minds are that closed. People will think what they think.
I used to wear 1 earring, then I wore 3, I had very short spikey hair too. Some people thought I was gay. I had DS. I've been a lone parent for quite a few years. I have DD, I'm alone again. I don't show any signs of being interested in men. Or women. I don't think I will again.
But - I'm straight, I've been married, divorced and widowed. I don't think I have the energy for another relationship.
But people will think what they want to think. You need to be confident about who you are......