Miranda, your dolls are so lovely
I know you asked for helpful tuts, so here are some sites that I like(besides Watermelon Bubblegum which I see has received much love here
I really like that site and suggest you use the jeans and shirt/top shading. All tops, even ones for dresses, would be shaded similarly to that.).
Het paars konijn: a pixel doll site
-The hair tutorial can be applied to other styles later on and is a really good idea to look into. Also, I enjoy her boots tut. Her other ones are back up yet since she just moved, but hopefully they will be soon.
Box of Pixels v.6
-I recommend looking at the skirt tuts. One is for the front and the other is for the back/under other fabrics. They can also easily be applied to dresses and shorts skirts with the same style.
Doll Tutorial Search Engine: Main
-I'm not sure how many of these sites are still up and I've found most are rather crappy, but I've stumbled upon some amazing stuff and they cover lots of different topics.
Overall, the best thing I can suggest to you is to look at other people's work. When I don't know how to do a certain style, I always find it helpful to look at places like the Doll on the Hill Factory or Watermelon Bubblegum or even just to search it on deviantart(dolls are under customization when you browse).