Here is how I do mine. Like I said its informal but you will get the idea.
Glam bands are made with glitter tape. The kind you buy for hula hoops and reflector items.
The cheapest place I have found glitter tape is www.identi-tape.com
Cut your tape into strips…the typical size we used for them is 20 inches unstretched.. So we would cut the tap to 15 inches. Then cut a piece of backing to the same length… we used 7/8 black velvet for the backing. The glitter tape is 1 inch wide so you will have to trim down on the tape. I found it easier to trim at the end. The cheapest place by far to get 7/8 inch velvet is united bead.
You will need a fusible webbing to bond the glitter tape to the velvet. The glitter tape is sticky but you will want to make sure it bonds. We used 7/8 inch heat bond to bond the glitter tape to the velvet.
You are going to iron the heat n bond to the backside of the velvet. Once it cools peel the paper from the heat n bond leaving the webbing on the backside of the velvet. I use a mesh guard under my iron since velvet is pretty tricky to iron without matting it down.
Next you are going to adhere the glitter tape to the back of the velvet with the heat n bond to the sticky back of the tape. Once you have stuck the tape to the velvet, you will again need to iron in order for the glitter tape to bond with the velvet. Run the iron over several times to ensure there are no bubbles and you have a good stick.
This is when I trim the excess glitter tape that is over hang on the side.
Now you should have 1 piece of 20 inch glitter ribbon with a velvet back.
Next you are going to cut your elastic. I used ¾ inch non roll black elastic that I found a good price on eBay for. Cut a 5 inch piece of elastic. Sew each end of the elastic to the velvet side of each end of the glam band. Trim any extra. I used 3/8 black grosgrain for the casing. Just wrap your 3/8 black ribbon around the seam where the elastic meets the band to make a finished look.
You can adjust the measurements as you see fit if you want to do different sizes.
If you have any questions.. Please feel free to email me. I will help : )