Keep it safe from being stretched: Even if there is a little bit of carelessness in handling new and well fitting jeans, it can cause the wear and tear of your brand new jeans due to overstretching. Thus, care should be taken to keep the fabric as stable as possible so as to avoid puckering of the fabric. Although the denim material is known for its durability, still cutaway stabilizers should be used to keep the stitches crisp to avoid it from getting wrinkled. Get the info from here.
Choose your designs wisely: Since the denim is a tough material, designs with large embroideries are preferred on it rather than the ones which are so fragile that they seem to get lost in the fabric. One could also try doing appliqué work on them since the sturdy material of the denim is best suited for heavy embroidery appliqué work.
Contrast the designs with the background: In order to avoid making the denim look monotonous, you can use the designs in contrast to the colour of the denim. Care should be taken not to wash it too regularly otherwise the design might fade away. Designs make with dark colour threads lasts longer, thus they are preferred over the lighter shades.
Choose the correct thread type: Threads should be chosen in such a way that their colour stays bright and radiant even after several washes. Polyester threads mixed with rayon have the strength as well the colour durability and are hence used for making designs.
Recycle and reuse: Since denim is a very durable fabric you might get bored of wearing the same jeans as it might not get torn. In these situations, all you can do is to recycle it and reuse it, maybe as a cushion cover or as a traditional bag and make customised embroidery on them.