Hi,
use some scrap fabric. I have embroidered names by free motion. Drop the feed dogs, bring up your thread. But first trace the names on several sheets of paper, then practice writing them. Have the paper and writing same size of the cuff you will be using. This helps the mind remember the motion of cursive. Just remember to relax, move your fabric slowly ; sew as if you were writing with a pen or pencil. It takes a lot of practice, but eventually the flow will come. You could also use a pen made for fabric to put a personal touch to your work. Good luck