If option 1 isn't possible. Let us send you a free finger sizing tool! If this is a gift to yourself, perfect! We can send you a small tie that will sufficiently show us your size.
One other final option we have for you, is to mail in a 'borrowed' ring of theirs. If you can get your hands on one of their rings, you can send it in for us to size. Even if the ring sits on a different finger, we'll be able to closely estimate the size you need. Once again, just get in touch to organise this option; email@example.com