Item Rejection

I submitted a WordPress Plugin for first time and got rejection with mail with below words. unfortunately we found it isn't at the quality standard required to move forward, and you won't be able to re-submit this item again.

Is it possible to get a skeleton of approved WordPress Plugin ?

Could anyone share any effective guideline to approve WordPress Plugin ?

I am going to develop another small WordPress Plugin to submit as experiment. I need to know what are the quality standard.

Thanks.