Once if you enter into Ecommerce business and set up your site you main objective should be bringing more traffic to your site and this can be obtained by optimizing your site better for SEO.
Below are some of the Onpage checklist for your Ecommerce Site
Meta Tags : (Title, Description, Keywords) :
Meta tags are important for any kind of ecommerce websites. Best practise is to include your keywords in Meta tag both in descriptions and keywords.
URL Optimization :
You should have SEO friendly URLs so that google can better understand about your pages.
Alt tag for Images :
Image optimization is also a important part in optimizing the website. You should save the Images with keywords included and also include alt tags for Images as google can read it better.
Product Descriptions :
You should have a product descriptions without fail for all products and it should not contain any duplications. You can have unique product descriptions instead of copying it from other sites
You should always interlink your page from one page to other. Always you can have a link to your homepage from all your inner page
Header Tags :
Include Header tags like H1, H2 and H3
XML Sitemap :
Include a XML sitemap for all your products so that google can easily crawl your products fast as possible.
Page Loading Time :
You can increase the converison of your page only if you can reduce your page load timing.
Include a robots.txt and instruct google what not to be crawled. You might have some restrictions about certain pages and you might not want those to be crawled by google.
Social Sharing Buttons :
You should have social sharing signals so that users can easily share the necessary things througgh their social platforms.
Adding a Blog :
You should definetely add a blog and try adding content frequently to it. Having a blog and updating content frequently will increase your ranking in google SERP.
Product Reviews :
Adding product reviews gives some sort of trusted signals so that it is easy for buyers to decide on buying the product.