What you will need:
- One ill-fitting wig
- Threaded needle
- 2" length of 1/4" elastic
The doll I'm demonstrating on is an MSD-sized American ball-jointed doll ("Secret" by Goodreau) who usually takes a 7"-8" wig. If your wig is for a different size head, you may want to cut yourself a length of elastic a little shorter or longer than 2". Rule of thumb: when stretched, the elastic should go around about 1/4 of the head's circumference.
3. Try the wig on your doll's head. If it still seems a little loose, un-stitch the ends of the elastic and stretch them further towards the front of the wig cap before re-stitching them. If it seems to be staying on, then you're done!