Another option is you only want to embroider on a stocking cuff on a presewn stocking is to use the "hoopless" method. Hoop your stabilizer (I recommend a nice cutaway) as normal. Give the stabilizer a light spritz of a quality embroidery spray adhesive (I like the 505 brand). Flatten the cuff and place if on top of the slightly sticky stabilizer. Use a basting design to help attach the cuff to the stabilizer then embroider as usual. Note you'll have to be careful about positioning the design, but you should be able to do that. When the embroidery is completed, unhoop the stabilizer and trim away the excess. BTW: You probably want to use a water soluble or iron-away topper on top of the cuff before embroidering; most cuffs are a bit "fluffy".
Pam