It’s not the most animal friendly topic so far, but there are communities, people and cultures who base their livelihoods off of using animals for their fur for clothing such as trousers, jackets, coats and parkas especially those who live in Northern Canada and Alaska where that’s part of their culture for centuries (going so far to be documented by European explorers in the early modern period). There are even animals who’re domesticated and farmed for their fur, most notably American minks and red foxes.
These animals would have to be fed and cared for before being euthanised for their fur, usually through gassing or electrocution in order to be skinned. As gruesome as it sounds, that’s how they use the animals for their fur. This has raised the ire of some people who even get fur farming banned for good in some countries such as Britain and Ireland for instance, even if that results in more invasive species (as in newly introduced species wrecking havoc on the environment they’re in).
Then they stretch the skins and have it be patched and sewn when made for clothing at all, which the numbers vary depending on the animal being used as well as how many hours it takes to sew such a garment that it takes 40-100 hours for a fur coat to be sewn but less if it were just cuffs and collars. For the Inuit and their habit of using seals for clothing and meat, this takes much longer as that involves softening the fur from chewing it constantly and continuously.
For sewing furs and possibly leather, a special needle is used which’s thin and strong enough to penetrate the flesh and have it be sewn to other patches of fur to make a garment which was the case before the invention of the sewing machine for a long time and still is so to some extent, possibly a great extent, today. It’s called a furrier’s needle, which’s the sort of needle used for sewing furs with and possibly leather when one considers this. Even today, some people use needles to sew fur with and even then it has to be done with a special technique.
Fur clothing has been around for a long time in whatever form, whether if it’s an entire pelt of fur, several pelts of fur stitched together to make a garment or patches of fur stitched onto woven garments.