"Depth, Complexity, Quality"

I'm linking to a page from Professor John Lye at Brock University that might help you understand better what makes a quality piece of writing, whether it's a poem, a short story, or a novel. The page is titled "Depth, Complexity, Quality" and gives some characteristics of those concepts.

Professor Lye starts by writing:

A common way of identifying the qualities that characterize literature as 'good' is through the concepts of depth, complexity and quality.
The basic idea behind depth and complexity is that literature, as does any art form, represents human experience in a way that is both revealing and compelling, that tells us something about the world, holds it up for our examination, and does so in a way that engages us. This telling about the world will also tell us about ourselves, about the nature of human experience.

As there are local as well as broader components to any understanding of the world -- values and ideas which are common to a particular place and time as well as those which tend to encompass large numbers of groups over time -- fiction will also tell us something about the specifics of a time and place, about how a certain group or time saw the world.

The skilful use of the resources of the art form in evoking depth and complexity is known as quality.

He then discusses each concept briefly. It's not a long page, but might help you think about the use of these concepts to give your writing depth, complexity, and quality.

Professor Lye also has a page called "Critical Reading: A Guide" which can give you some help with analyzing literature, as well as noting things that will make your own writing better. These pages are written for college students, but, if you're like me, you can learn a lot from these types of explanation.