By now I have read some much information on Etsy and online craft selling that I not only feel a bit over-whelmed, but indebted to a few key resources.
Firstly, if you are considering opening your own shop on Etsy (or any other online venue), you must check out The Storque Blog for detailed information on selling, setting up shop, and marketing yourself. It is well worth the time and energy to read all that you can here.
Secondly, as recommended by someone on Etsy, you must get your pretty little hands on a copy of The Handmade Marketplace: How to Sell Your Crafts Locally, Globally, and Online by Kari Chapin. You can find it all your local bookstore or at Amazon. Chapin is really good at covering the nitty-gritty without blowing your mind. She's included a lot of input from big players in the handmade marketplace and it is illustrated by one of my favorite artists (and apparently the top seller on etsy.com), Emily Martin of The Black Apple.
Thirdly, if you're not already, become a buyer of handmade crafts online. Obviously I recommend etsy.com but there are many other online marketplaces to try out. Not only are handmade items and communities more unique, but Etsy does a good job of maintaining secure and positive transactions. It will also give you the chance to experience what you do and don't like about online sales.
For instance, I have discovered that pictures really do tell a thousands words and that I don't even bother with shops containing fuzzy, cluttered or hard to see pictures. I want to be able to almost feel the product before I buy it and quality pictures from many angles really help. Also, detailed product descriptions are not something to skimp on. I shouldn't have to email a seller to get more specific information about a product as that wastes my limited time. The description doesn't have to be a drag either. Quirky back-stories draw me in and help me to further connect with the seller. Can you tell I am a sucker for words?
Unfortunately, I am also a sucker for eye candy. Sometimes I actually Google search Images with the key word "beautiful" or "enchanting" just so I can feast my eyes on a variety of visual inspiration. That means that those shops with beautiful banners or Flicker links with additional pics of their products always attract me faster than the typical shop. A brand-image helps too. If all your products, pictures, etc. fit a theme or are aesthetically pleasing at first glance you instantly strike me as professional and talented. I understand the whole "don't judge a book by its cover" but our modern world is full of fast paced imagery and you have only seconds to attract a customer, so make the most of your visual opportunities to captivate your audience.