Shiraya Makes a Tiny T-Shirt on Tumblr

Shiraya's Wardrobe on Tumbler has a bunch of great tutorials, including one for putting a fly front on tiny doll trousers that I need to study (I am so bad at sewing pants). The post that caught my eye today was one on making little stretchy T shirts; you have to figure out the size yourself, but there are step by step assembly instructions with photos on how to do the neckline and sleeves. If you are not on Tumbler, the key points were: to make the neck facing out of a bias-cut bit of stretchy fabric with a slight curve "like a smile," and use a stretch stitch when you attach it to the shirt, so it will stretch enough to get over the doll's head. For me the best tip was how to assemble the whole thing, so you are not trying to set in those tiny sleeves into an assembled body piece:

Having the shirt spread out like that means you can also top-stitch the sleeve caps, which makes it easier to get hands in the armholes and keeps the sleeves from popping out at the shoulder seams. Since I don't like pulling tight stuff over faceups, I would cut down the center back a little, and put more bias edging over the cut edges, and put a button-and loop closure on the back of the neckline to close it.
Shiraya also has an Etsy if you prefer your T shirts ready made :D