First you must know your products (advantage and disadvantage) of it, second use any social media that you can promote your products, most of the people use social media, there is a possible that more people can view your products. Third you must know your target market, most of the buyers are in your target market. Fourth you can create a blog or website to look like professional, and Lastly always show your proof of shipping, customers feedback etc to know your customers that your legit reseller.