Of course. I've always maintained a policy that people can reapply later if they wish. Generally I suggest a wait of 6 months or so, but nothing's concrete. What I do ask is that you feel you (or your site/art/etc.) has significantly changed in some way before you reapply. I've had several people come back with almost an identical application, even linking the same pictures... I don't change my mind without reason. So yes, work on your art, get better, come back when you think you're ready. And best of luck!