I can't help with the stretching part, but as for attaching there are a couple of ways. The way I do mine is by placing the RBC on the cookies after they come out of the oven. I allow them to cool a couple minutes and then place the RBC on which will slightly melt and adhere to the cookie. I learned that on CC and it works great. I've also read that some people attach with corn syrup. Rub CS over the cookie and then attach RBC. I've never tried this method so I can't advice, but it seems quite a few people do it so it must work out alright. HTH.