Not to forget, the more you sell, the more you re-list and get noticed.
If art is your thing, maybe think about making your art into gifts, pendants etc, have a look at other successful art shops and what they are selling. The ones I know have gathered a following via facebook and blogs.
I do plenty of research to see what's out there in my genre and which gaps I can fill.
Also, being active in the teams and faving items and team treasuries helps.
Pinterest is really good too as is writing a blog, they lead people into your shop via links.