What Should I Expect From an Ecommerce Website Design Project?

I’ve been helping a relative plan an online store, and we recently started comparing different approaches with an ecommerce web design agency. We initially focused mostly on how the website would look, but then realized that usability matters just as much. Product categories need to be easy to browse, pages should load smoothly, and the checkout process shouldn’t feel confusing. We’re still working out which features are actually necessary and which would just add clutter. I’d be interested to hear from people who have launched an online store. What design decision made the biggest difference for your customers?