As some of my jeans are loosed and I have to tight all these so I Can wear these again. Is there any other way to tight jeans except stitching?
Wet the jeans in hot water and put them on wet. go outside and allow them to dry in the sun in the course of an afternoon. When dry, remove them, rewet with hot water, and repeat. This is how "cowgirls" get skin-tight jeans in the US.
Wash jeans in hot water and dry it in sun light. Repeat this step when your jeans become perfect to waer. Button or zip them up so they fall as they would when you'd wear them. Stand in front of a mirror. Note the areas where you would like the jeans to fit more snugly. Then place button or zip them that place. Find a place that can be cover under your belt. Boil jeans in water 5 to 10 mint.