I'm not sure what you should make more of. A good indication would be what gets more views, what customers buy more of, what style they choose when they place a custom order. Then test some new ideas, if you wish, and see how it goes. As for the holidays....Halloween or Xmas theme might be appealing....
Aesthetically, all looks good to me. There is a cohesiveness in your shop, all blends well together and it's very clear what you do. The custom order options are very clear too.
Something that stood out...I think the writing in some of your photos on the front page of your shop might be too large in comparison to the small product you are photographing. Maybe it's just me, though...