First, prepare a small piece of elastic belt, with a layer on the inside of the back of the belt, and draw two crosses according to the tightness. Insert the elastic band into the center of the two openings, sew one of the openings with the elastic band with a needle and thread, then pull the elastic band to the tightest position, and sew the other end of the elastic band with the other end of the opening with a needle and thread. It's best to cut off the rest of the thread, which will be more beautiful, smoother and more comfortable to wear, so that there will be no hard feeling at the back.
The belt can be flexible according to the change of body shape. Be careful what your friends say. Don't spread it too wide, just like an elastic band. If it is pulled too wide, it will not only be difficult to sew, but also damage the beauty of pants. The color of trousers sewing thread should also be as close as possible to the color of trousers itself, otherwise the color of the thread will be different, which is obviously detrimental to the overall appearance.
In fact, this sewing method has no effect on the appearance of the whole trousers. If you don't look carefully, you won't see the modified pants. If you wear big clothes, you won't see them in disguise. In fact, for some people who have no sewing experience, this method is more difficult. Another very lazy and simple way is to wear a belt. The belt itself has mediation function, which can be adjusted according to your own needs. However, sometimes wearing a belt will wrinkle your pants and make them uncomfortable. It is very useful to wear a belt in case of emergency.