Work on getting bright, crisp photos. You may need to use a photo editing software to get what you want, but start by taking your photos in natural day light or a light box.
Consider shipping to other countries (and don't be afraid to charge for shipping! your buyers are willing to pay it, I promise!). Nearly 50% of my sales come from other countries all over the world.
Most importantly, add more inventory! You can't sell what you don't have listed! I know it's much easier said than done, but if you focus on increasing your inventory and set goals for yourself (3-5 new items a week, for example), it will really pay off!