I opened up a shop on etsy.com today. I've posted some sweaters for 11.5-inch dolls (I hope to post other types of items in the future). You can visit the shop here. These miniature sweaters were very fun to create. They are all designed and handknit by myself.
Most of the sweaters are knit using size 10 crochet thread and sock knitting needles. I like using the crochet thread because it is relatively inexpensive, comes in a wide array of colors, and is readily available from any store that sells craft supplies.