I love packaging! I don't use coupon codes because I haven't found them to be useful in the past (although I only tried them once).
I usually package my items in a cello sleeve and include a business card or packaging label that has my shop name on it. I often throw business cards away that I get in packages, so I've been trying to incorporate my shop name into my packaging. Like this, with the band going across the middle:
http://www.etsy.com/listing/82002148/kraft-tags-paper-lace-12-tags-large Each item is packaged slightly differently based on its size. I put each into a small manila mailer or small padded mailer based on the item. Recently, I've been trying to include a little thank you note since I read somewhere that buyers like that sort of thing. I also always print out a label instead of handwriting it. Then it's ready to go!