1, find a sewing thread with the same color as trousers. The sewing needle should not be too thick. Try to choose a thinner sewing needle. Thread a thin thread into a pinhole and tie a knot at the end of the thread.

2. Open the seam of the trousers to be sewn a little, see the original seam trace, insert it from the back with the prepared needle and thread, and start sewing along the original seam.

3. Each needle should be stuck on the original trace a little bit, and the needle sticking method on the left and right sides is the same.

4. When sewing each stitch, don't pull the thread too tightly, loosen it a little, make it even, and don't have too many stitches.

5. When sewing the stay wire, pull it forward and upward smoothly, otherwise the seam will not be easy to flatten, and even the seam hole will be easily widened.

6. After sewing (about half an inch in length), gently tighten the sewing thread forward and upward along the force, and the sewn seam will be smooth and perfect. Finally, put the tail needle on the reverse side and tie the knot.