The first and easiest is to wash the jeans in hot water. To do this, put them in the washing machine, check the temperature of 95 degrees. After the wash cycle is finished, stop him (before in the car again poured cold water to rinse) and re-run, but without powder or any detergent. After washing, dry the jeans or at a maximum temperature in the drum of the machine, or on a hot radiator or in the steam room of the sauna.
This method has a significant drawback. After a few days socks jeans can again be stretched and return to its original state. So periodically have to wash jeans this way again.
There is also more time-consuming option, but at the same time more effective. It is for those who know how to sew. Jeans can easily take in side or rear seam.
If the jeans you are great in the waist and hips, then take in them have on the sides. This would be easy even for an inexperienced seamstress. Side seams rip, and then say, where a new line and smatyvay thread. Next comes the fitting. If all looks good, then sew the seam again to try and only then cut off all unnecessary.
If jeans are great mainly in the waist, to take them better at the back seam. At first, carefully unpick the back belt loops. After that, the belt is cut strictly in the middle. On each half doing a tuck, which removes excess tissue. The amount of this extra tissue is determined during the fitting. Tuck should not be done too long, otherwise the back pocket will begin to puff up. After the belt is removed all the unnecessary, sew it neatly back to jeans. Belt loops back.
Even one fairly simple way is to pick up the extra fabric in the waist Darts.
Are these Darts along the side seams, so they do not spoil the appearance. This pre-slit finishing stitching the side seams, so it does not interfere. This method is applicable only if the jeans are quite thin - not all home sewing machines can handle multiple layers of fabric.