Voodoo dolls are simply focuses(stand ins) for a magic practitioner to send energy to another Though the doll itself is neither black nor white magic, caution should be used. For the doll to be effective, a strong link must be made between the doll, the person receiving the energy and you, the practitioner. When done correctly, a doll is one of the best tools for healing.
Dolls can be made from just about anything that can be fashioned into human form(try not to use anything too degradable) like fabric, wax, corn husks, polymer clay etc...I prefer fabric dolls because it's easy and I can add herbs and oils to the stuffing along with physical links to my subject.
To make a doll:
-Start on a new moon, work on it each night until the full moon.
-While working on it, think intently about the person it represents.
-Make the doll as detailed as possible. The more it looks like the person, the better.
-Add objects that link the doll to your subject, like hair, nail clippings, blood, pictures, their favorite scent, photos, astrological symbols etc...
Once the doll is done, it can be used in any working to stand in for your subject. Treat the doll with great care, even when not using. It has your energy in it too.
This page includes a list of colors for pins and their meaning. There's several pages out there if you use Google. I searched for "voodoo doll" a couple months ago and found out so much once I sorted through the sites that are selling something. I've never used a voodoo doll, but it's still interesting.