I knit the length of the mitt for 6.5 inches before starting the thumb gusset.

I did not love the thumb gusset. I’m not sure what would make it better. Becase there are increases, it needs to be decreased, and the designer put all the decreases at the thumb. It made the hand a little goofy over by the thumb. Perhaps it would be better to space the decreases evenly across the hand? Or work the thumb differently all together? Not sure what the best fix is.

The pattern is well written and easy to follow. If not for the odd thumb, I would knit this again.