You can undertake multiple steps to ensure that your website is mobile-friendly and responsive. First, choose a responsive ecommerce platform or theme such as Shopify. Second, improve the speed of your website through minifying, caching, and Content Delivery networks. Third, use legible and consistent topography, and finally use different website responsiveness tools such as Google Mobile-Friendly Test, Responsive Design Checker, or BrowserStack to ensure optimum mobile friendliness.