Composition is both simple and difficult . . . but since it's important, I will be spending a great deal of time in the near future adding examples and instructions to help master the art of converting your photos into art.
A photo composition is comprised of the following elements: your subject, the background, the secondaries (other props and objects), the lighting, and the angle and position of the scene within the photographic frame.
As an online seller, you want your product photos to catch the eyes of potential customers and leave them with a feeling that you're a true professional. A good photo composition is how you achieve those desires and make a good first impression.
For most people, learning how to compose a photo is the most difficult aspect of the whole ordeal. It involves having an eye for artistry. But, there's an excellent (and free) way to develop an artistic eye.
Visit any of the online selling venues (Etsy, ArtFire, Ruby Lane), and do a general search for "jewelry".
Scroll thru the pages quickly and casually. As you do this, you'll notice that certain photos catch your eye. For some reason, they have the power to draw you in. When you find such a photo, take time to analyze why it appeals to you. Then adapt that compositional element into your own personal style to create your own powerful compositions.