Whether you've gone through a recent weight loss, or are trying to firm up a recent purchase, shrinking your jeans is a great way to adjust your favorite denims to your shape. There are several ways you can shrink jeans, as their cotton-based material is naturally prone to shrinkage under stress and high heat.
Hot Water Wash
The easiest way to shrink your jeans is to wash them in the washing machine using the hot water setting, and then putting them in the dryer on high heat. The warm temperature will cause the cotton in the jeans to shrink, and the high heat from the dryer will help accelerate this process. However, the only downside to this method is that it may take a few tries to get your jeans to shrink noticeably.
Boiling
Boiling works a little bit faster than just throwing your jeans in the washer. Simply boil a large pot of water, and then add the jeans once the pot really starts rolling. Keep the jeans in there for 20 to 30 minutes, and then throw them in the dryer (on high heat). This method will produce dramatic shrinkage in a short amount of time, but the actual level of shrink will vary depending on the style and wash of the jeans.
Hot Bath
The best way to shrink jeans to your size is probably the most uncomfortable. Put on your jeans, and then draw a bath of very hot water. Then sit in the hot water while wearing the jeans for about 5 minutes. Then wear the jeans around the house until dry. The jeans should now fit to your form. Note: this method can also be used to stretch jeans as well.