Need some suggestion

I need some suggestion about design that I will follow to make my own designed psd. Could anyone please give me some suggestion? Also overall to publish a theme on this large marketplace. Because I can develop web sites. Thanks.

Look at other themes on themeforest then make something unique

Thanks benSheppard. I have looked several theme but I am confused because I think all designs are quite same. Mainly I am looking for joomla theme design. All fetchers are quite same just a little change. Now if I want to make a unique one then do i make a complete total unique one or some fetchers.

Thanks again for your supportive reply.