One great way to impress your customers is with how you package your products. Boring packaging may work well for mass produced merchandise, but people often hope for more from artisans. In the purchases I've made on Etsy, I've seen quite the range of packaging.
Some are just placed in the envelope and mailed, while others place items in bags, boxes or paper before putting them in the envelope. I don't think any less of those who don't do anything special, but I will never forget the people who go to the extra effort. It can be as simple as a nice handwritten thank you card or as elaborate as gift boxes. Many sellers like to add something "extra" like an extra piece of jewelry, some beads, or some little trinket. There's even a Flickr group that focuses on Etsy packaging.
feature on Leslie Witmer? She definitely knows how to wow her customers with packaging. Check out the hand-folded box she sent her jewelry in! It shows off the jewelry incredibly well and she attaches a custom label and even a little bling. I can't bring myself to throw away the box and she has made a big impression on me.
I haven't done a whole lot with my own packaging yet. I have ideas, but I always seem to run out of time. It's not much, but I do include a small thank you card and wrap the item in tissue paper. How do you package your products? What's the most memorable packaging you've seen?