Knit-to-Fit seamless fingerless mittens
Most flat knit fingerless mittens don't have thumbs and may have a seam. The difference with my pattern is that you knit the thumb as part of the mittens and you don't have to mattress stitch a seam, they are seamless.
This pattern is (hopefully) an easy to follow, step by step, recipe for knitting fingerless gloves on 2 needles, so flat, using the following techniques:
Provisional cast on
Short row shaping
Wrap and turn
And you will be knitting them to fit your own hands, or the hands of family etc, so not just for adults, with the length of cuff you want. To do this you will work to your own gauge with the yarn you want to use. Follow these guidelines and this should result in a pair of fingerless mittens that fit you nicely.