Davy Fireskull: I have a few. My main one is that I always wear my French Tattoo on my arm. Oh, and we can't forget that he is a total fashion freak. My trademark clothing item I'd say is my White Puffy Shirt I got from the Tortuga Clothing Quest.
Tiberius Fireskull: His hair. For sure. He usually wears a hat, but on his head, he has a tiny little square of hair towards the back of his head with a little pony tail sticking out. Hardly anyone has this hair. Looks like this:
My other pirates, I play on so little that they really don't have any special trademark.