Basically, I look a lot like that doll at the right end of the top row. Freshly washed, my hair is dark blond spirals strong enough to break an "unbreakable" comb. Once combed out, it turns to a frothy near-afro and eventually to flatter waves.
If you make or modify your own dolls, look closely at the offerings in the craft store. Sometimes you can find curly or nappy hair to put on them, or straight hair that will hold braids. For dreadlocks, try felting or natural yarns. Fancy yarns can also simulate nappy or other textured hair.