Shorter version (30 sts cast on with some DK weight alpaca, also size 7 needles):
Yarn: Mystery mohair / wool mix I found in my stash. It's DK weight (around 22 stitches per 4 inches in stockinette). Gauge is not too important since as you are knitting you can decide how wide you need this.
Needles: Size 7 was used.
Cast on 30 stitches for a shorter version which ends at the wrist. The ones pictured above are longer and since they go below the wrist, I didn't sew around 3 inches at the bottom to make a slit. For the longer version you should cast on 45 stitches.
Slip as if to knit the first stitch of every row. Knit in garter stitch (knit every row) until you have a rectagular piece of fabric which fits around your hand, slightly stretched.
Cast off loosely. Use a larger size needle to cast off if needed.
Sew up the side seam, leaving an opening for your thumb. If making the long version don't sew the bottom 2 or 3 inches for a slit.