Get dirty. After purchasing a “stiff, raw-denim” pair of jeans, wear them as long as you can. The “longer you can go without laundering them,” the more comfortable they’ll be. If you prefer stretch jeans, wash once a week to maintain that “original snug fit.”

Stay true to your blues. To protect the color, always turn jeans inside out when washing. Use a “regular liquid detergent” and never set the water temperature “higher than warm.”

Give them some air.
Putting jeans in a dryer will “eventually reduce the elasticity in the fabric,” so be sure to air-dry “raw denim” and any pair worn loose. To shrink stretched denim back to size, set the dryer to “tumble dry at high heat for about 40 minutes.”

Hang out. Once dry, hang jeans instead of stuffing them into a drawer. Hanging them “helps mimic their natural shape when worn.” Use a belt loop at the back of the waistband as a guide.

Source: Allure