Hi Jen
Your pics could do with a bit of brightening. Have a look at this thread, there's heaps to learn here
http://www.etsy.com/teams/12647/ask-angela-friends/discuss/10388075/page/1/plus also I would like to see a pic or two with the slippers either being worn ( You only need a foot model here) or in context - maybe sitting beside a foot rest or bed - make up a still life including your slippers.
That will add a bit of pizzazz and make them stand out.
Definitely if you are going to use a plain background, keep it simple, clean, no creases ( try using a large sheet of paper, sitting the slippers to the front and having the rest of the paper leaning or taped to the wall behind (there are heaps of threads on making light boxes for smaller items)