How to Improve SEO Rankings for Already Ranking Shopify Product Pages & Collections?”

Hello everyone, I am a beginner in SEO and e-commerce. I am currently running a Shopify store, with the main source of users coming from Google's SEO. Over the past 10 months, some of my products and collections have started to rank and generate traffic. I want to continue improving the rankings of these product pages and collections. What aspects should I focus on optimizing for each separately? The things that come to mind for me now are adding high-quality product images, incorporating more internal links, writing blogs for content and internal linking. Currently, I haven't found any non-spam external links in this niche so I'm not planning to try that yet. Are there any other suggestions besides these? My second question is whether it's possible to modify and optimize the descriptions of these ranked product pages and collections? Or should I just add more descriptions?