It's not about doing a representational picture 'the correct way' because there is not one correct way. Your art is your interpretation of what you see. But you do need basic skills so that you can create what you see (and feel) rather than copying how someone else does it.
When I taught elementary kids I often reminded them that we have already seen my picture, or that of another artist, so don't make another just like that, that would be boring. But they could learn from basic art elements and principles in the example which enabled them to create what and how they wanted it to look.
As for the common artistic mistakes...
First, a good composition is not just a cool photo that you've taken and want to reproduce in fabric. Beginners often try to make a good picture exactly like a good photo. The thing is, you can probably make it better, much better. A good picture has a good focal point which can be emphasized by how the total composition is done. Sometimes there is so much visual noise in the piece that it's hard to find a focal point or find a calm place for the eye to rest. In addition, if the composition isn't cropped or framed ( i.e. by trees, a hedge, a fence, mountains) it may lose its focal point. There should be obvious or subtle lines in the piece that lead the viewer's eye around it.
Second, beginners often stress over finding the exact colors in the reference photo, but don't realize that the values (lights, mediums and darks) are even more important. Values are critical to emphasize or define or set apart shapes, perspective, edges, or contours. Interestingly, even though there is little variation in the colors in this picture, "Templestowe", 1899, by Sir Arthur Streeton, the focal point stands out in darker value than other elements of the scene, and your eye is led to it with the lightest value of the scene, the road.
Third, fabric choices are often made because the print in them really (really?) looks like the material in the picture. Fabric printed with waves, fabric printed with wood grain,
and my all time favorite (NOT) printed blades of grass, are often out of proportion, or out of perspective, or take over the focal point, or just look like, "Hey I found shingle fabric that really looks like shingles, so darn it, I'm going to use it!" The painting by Streeton has soil, leaves, grass, walls, roofs, weeds, etc but each of those things is actually a blob of color. If you pick fabric for it's blobs the viewer's eyes will fill in the details, or you could enhance the details with some thread sketching fun!
Fourth, color plays an important part in the feeling or mood of a piece. But how many of us consider mood over photo accuracy when creating? Beautiful pieces can have lots of carefully chosen and placed colors, and beautiful pieces can have a very narrow color pallette. Are complimentary colors used to their full advantage? Not often enough, I'm afraid.
Finally, beginners don't add details with thread sketching, or don't practice before they do add it. Remember the visitor to New York City who unknowingly asked an accomplished violin player how to get to Carnegie Hall? The violinist replied, "Practice, practice, practice." It's the same with everything we try to learn.
If you have questions or want to know more about these concepts, be sure to join my private, alumni only Facebook group, Bonnie and Fabric Friends. You must answer the 3 questions AND be a former student of mine to be allowed in.
If you send me a message (there's a 'Let's Chat' box at the bottom of this and every website page) about a question you have, I will not only answer you but will try to include the concept in my upcoming online class. The first class will be about incorporating meaningful and simple art skills and principles into your own art. You still have time to make an impact on what is taught.
Thanks for reading. I'd love to have you get active in our communications. Ask, tell, and please share this with anyone who may be interested.