The world of knitting and crocheting for dolls is at your feet, and you can do pretty much anything you want, especially for modern dolls.
One of my very favorite things to do for small dolls is split 4-ply knitting worsted weight acrylic yarns down to one ply, and knit with size USA 1/2.25 mm or USA 0/2.00 mm circular ‘square’ barrel needles. I will dedicate a page to that subject to share how to split the yarn down.