Jeans are special. They are tough by design. But you can tame the beast.
Soak new jeans in a bucket of cold water and a cup of salt for an hour. This sets the dye and relaxes the fibers.
After that, wash them inside out on cold. Never, ever use hot water on denim unless you want a stiff, sad pair of pants.
The Shaving Cream Hack (Seriously)
Here is the weirdest trick of all. Got a scratchy sweater? Grab a can of foam shaving cream.
Work a dollop into the fabric. Rinse it out with cold water. The glycerin and conditioners in the cream coat each fiber.
It sounds like a prank. But it works better than any speciality wool wash. You'll feel like a mad scientist.
How To Make Clothes Soft Naturally (Video) - Life Should Cost Less