I am going to mention few the most important things that you should go about regarding a design of your e-commerce website. Some of them are often overlooked.
1. You have limited time to get your message accross. If there are too many distractions, a visitor is likely to leave your website from a landing page. If you use Google analytics you can find "Bounce Rate" value which indicates exactly this (in percantage).
2. The visitors must learn as much as possible about the benefits about your products/services.
3. If your website does its job, you will likely have prospects who want to learn more or ask simple questions. Make them easy to contact you.
4. Clear call to action such as "buy now", "find more", etc.
5. Clear design (font easy to read, etc.)
6. If you are a small business you shouldn't pretend to be big. Your ability to relate to your visitors is a reason why they will eventually choose you. You should use conversational tone in your writing.
Hope this helps.