Hi! I get the same problem at the beginning and now, it's a little bit better.
The SEO classify the items by two ways:
1- relevancy of tags
2-popularity of items/sellers.
Hopefully, we can work on both.
1- relevancy: Title and tags are very importants, you can use synonyms or tearm as "shoulder bag" instead of only bag. Also, is good to change the way you do your titles: you must change the formulation for each item, dont start always by the same word "necklace". Sometime, start with color, style, vintage, OOAK, etc.
For more informations, it's a team about SEO relevancy.
2- The popularity: get viewed, so show your newest items, promote everything and you will have more and more clicks from researchs.
Good luck!
