Go to your gallery. Click on the image you want to use as your signature. On the RIGHT of the image, there are options to Share This Layout. You want to copy the text below "Share BB [ * IMG * ] Code:" (there won't be asterisks--used them so the site didn't think I had an image lol) and then PASTE that code into your Signature, which you can find if you click on your name at the top-right of your screen and click Signature.
Go here: https://the-lilypad.com/forum/account/signature and paste the code under the "Share BB Code" I love your signature! Do you remember where the skein is from? I need it! <3