How can i develop an theme to sell on themeforest

hi everyone,

i has working on several theme used on my own theme based from jekyll,
but when i tried to submit to themeforest, they rejected me with hard rejected.
either, they don’t special which is wrong, and i have none of idea how it is, maybe the way i code is not professional.

i love to learn, and love to develop some my own jekyll theme, as they could accept it, i want people accept at least one of it, so i can proud about what i working for people something useful.
please guide me, thanks

Can You Share Your Theme Files. I Can Help You , I have Some Approved Jekyll Themes In Themeforest.