Progress on mittens
When you've reached the palm of your hand, before the thumb begins, you need to make a loop that is big enough not only for just your thumb but also for all the thumbmuscles to be able to move with ease. Make sure you measure carefully! For me the width didn't have to be so big, because my hands are small so I only used 9 stitches to create the width. I needed 21 stitches to create the actual loop that goes around the thumb to be fastened on the other side, i.e. 9 stitches further on.
If your hands are bigger, use more stitches to get the right width and length!!
The cuff of the mitten is made by decreasing stitches rapidly after you've made the thumb-loop. For me, I went from 37 to 21 stitches. Fit each time you've decreased stitches! The mitten isn't very flexible, since I've used the Oslo-stitch (my favourite) but this means you have to be careful the cuff doesn't become too tight