The towering, jewel-bedecked church hats, for instance ... knit cold-weather caps; fedora-like rain hats; and Crocodile Dundee–style leather numbers, for even more rugged climes.

James Keith wanted to wear a fedora with his outfit for New Year’s Eve 2015, but he couldn’t find one that quite fit the bill. A year after he conceived his design, he finally got the hat he wanted on ...