Repair a large hole in your tights by using a technique called "darning," in which you cover the hole with a basic weaving that will mimic the rest of the fabric around the hole. This technique is most commonly used when repairing knitting in socks; you will just need to use the right thickness, color and type of thread to fix your tights in this manner. Find the materials you need at the craft store or the fabric supply store.
Stick one of your hands inside the tights and position it under the hole you want to repair. Brush clear nail polish on the edges of the hole to prevent the fabric from fraying and to keep the hole from getting bigger. Wait 20 minutes for the nail polish to dry.
Thread a sewing needle with the same color of elastic thread as your tights. Bring the needle up through the fabric, about one-quarter inch away from the far-left top-edge hole. Pull the needle back down through the fabric, one-quarter inch away from the bottom edge of the hole directly across from where you started.
Bring the needle down and up, one-sixteenths-inch directly to the right of where you left off. Run the thread across the hole and pierce it back down through the fabric so that you now have two threads running vertically across the hole. Do not tighten these stitches — they will act as the "warp threads" of the weave in the fabric. Repeat this process until you have made warp threads across the width of the hole.
Run one-sixteenths-inch-long stitches back and forth in the fabric on the edge of the hole to secure the end of the warp threads. Finish with the thread going down through the inside of the tights and trim the thread.
Thread a darning needle with the same color of elastic thread as your tights and go back and forth in one spot on the upper-left edge of the hole to secure the end of the thread.
Weave the darning needle up and down through the warp threads across the top edge of the hole. Go back and forth across the top edge three times to make the weave as dense as possible, so you won't be able to see through it and it will blend in with the rest of the fabric.
Weave across the warp threads, back and forth, and push each new row of weaves up against the last. Continue until you get down to the lower-right edge of the hole and the holes is completely filled in. Secure the end of the thread and trim the excess.