How long did it typically take to make a ceremonial indigenous head dress?

If you mean native American ones with all the feathers, often they are eagle feathers, and it takes a lot of work.

@Zaku Yes. Thanks.

Not all tribes wore the same stuff. Can you specify which tribe you are referring to?

@kritiper No. Just wondering.

Keep in mind, their entire days were spent at home. Other than hunting days, and days of battle, they kept busy crafting utensils, tools, clothing. If two days or two weeks was spent on such a project, when it was finished they started a next task. Some duties, such as gathering grains and herbs could be split up, so some would stay home as security, and to keep up with individual duties. There was a lot of detail work for ceremonial costumes, but the women of those times were well practiced, and capable of completing some very impressive handiwork rather quickly.
Did you know urine was used to get certain desired effects?

The tanning of a buffalo or deer hide could take as long as a month and a half, depending on exactly what it was to be used for. Certain head coverings could be made of a wide variety of things such as coyote, fox, wolf skins, or even dried birds like blue jays or woodpeckers. Feathers could be from a wide variety of birds, depending on just what kind of birds were in the area where the indians lived or traded. Crow, magpie, duck, goose, pheasant. You name it. How a indian dressed was a mark of individuality and many if not all found great pride in that individuality.