Leather and similar fabrics, such as vinyl and pleather.

Special tools – examples :
needles for sewing (p)leather,
– thread (polyester not cotton),
presser foot (example of a foot that has a non-stick sole so does not stick to (p)leather while stitching). For another option see below.
clips, not pins – make sure not to make holes in the material being sewn, except along seam-lines. For basting tape, see below.
– a robust sewing machine, able to punch through 2, 3, perhaps more layers of (p)leather without straining.

Most sewing machine brands have a presser foot like that.
There are many other manufacturers for the needles and clips too.

Special techniques :
I particularly like this video of someone skilled making a leather bomber jacket.
No commentary, so you need some sewing experience to work out what is going on and learn from it.

The stitching in this video is done using a specialised industrial machine. It is similar to using an ‘edge stitch’ presser foot on a domestic sewing machine. These feet have a flange which you run the edge of the fabric/leather along. Here’s the Bernina version.
edge stitch

Use a longer stitch.

I found these two brands of special basting tape for leather but have not tested them. (I couldn’t find them on amazon.com.). Note these are ‘basting’ tapes used to hold the leather in place temporarily while you stitch. They are not intended to make a permanent bond.
Prym.
Tandy.

Many more guides if you search “sew leather on machine”.

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