Hi Jasmine,
You're right; it's always good to review, update and and try to improve. Here are my suggestions:
Photos: I'm not too keen on the beads casting dark shadows on the background. I prefer a simple background rather than the checkered one. Perhaps try photographing from different angles under natural lighting, or have someone model your necklaces. That would really show how your creations look on a person.
Tags: Repeat keywords exactly from your titles in your tags.
https://www.etsy.com/listing/125969385/layered-seashell-necklace-with-copper?ref=shop_home_activeFor this listing, tags could include: layered necklace, seashell necklace, copper beads, beaded necklace, iridescent beads, natural style, earthy style, brown beads, tropical necklace, seashell gift, etc.
Hope this helps, and good luck with your shop!