Teach Me Please (PSD)

Hello My dear envato people,
I would like to create a PSD website template in the education category. So, guide me to make a better performing website template to give a good response as Wordpress or other development process. Because I have saw many education themes in themeforest, But a small number of themes only getting a good sales and fair response in the market. On seeing these kind of themes, I don’t understand what kind of content I have to give in the PSD template? I mean, As a template designer, what I have to design in My template to make it into a successful WP theme or CMS development.
Is that based on the developer (Partner) or it’s about the Number of Pages, Template Name, or Advertisement of the item?

Thanks in advance for Your Guidance