1. Social Proof. Most people like to follow the crowd, and if they don't see that other people are buying your product, they won't either.
2. Clean Product Images. if you're using low-quality or generic stock images on your site, most of your visitors are going to instantly recognize this, and peace out before you even have a chance to sell.
3. FAQ. Your customers probably won't take the time to email support and wait for a response if they still have questions- they're just going to go to your competition.
4. A clean and consistent color theme. Limit the number of colors you use to make sure it's clean and professional.
5. Calls to Action are clear & stand out from the rest of your page. if a 5-year-old old cant figure out where you want them to click, you're losing out!