Some entertaining spellings from the 1500s:
Typhanye, Tyffayne, Tyffina,
Tiphanie,
Tiphaine (these last two are still in use in
France) and Tiffin / Tiffen - now one of the relatively rare examples of a surname derived from a female name, as is
Tiffany itself. And yet despite the historical interestingness of it, I don't like it. The jewellery brand makes it feel far more like a trendy surname-name than a medieval survival. And the sound is so fluffy, like taffeta and frippery.
I do quite like
Tiphaine, though.