I have taken my avatar, which is my basket of yarn and fabric and that is what I use across all sites. It is my banner, my avatar, it is on my business cards, thank you cards, my blog and my FB page. I think it is necessary for people to start to know your brand. For people who use their photos, I would say find a pic you like of something that relates to your shop and start using that everywhere.
It just takes time. I just heard from a customer that bought two of my pillows and it sounds like she might buy two more. Just keep at it. When you send an item out, make sure you enclose a business card or two. I offer a 15% discount on a return order. I also send a thank you card.
People don't get this kind of treatment from those big box stores. You need to show then it is much more pleasant to purchase with you!
Don't give up. I have only sold 7 items, but I have not become discouraged. I just keep at it.
List your items on all the free advertising sites that you can.