A rule of thumb with ribbing is you make 2/3rds the length of what you are putting it on to.
An example would be if the wrist of the mittens measured 12 inches you would cut the ribbing 8 inches. You then slightly stretch the ribbing to fit as you sew.
Good job on your test run.
awesome thanks I will do my best to remember this for the next one. I appreciate it very much.
I would say a little smaller ribbing. I like my gloves to fit snug. But look great.