Build an email list. There is a system for working with leads. The first step is getting them to be aware of and take an interest in what you have—by visiting your website, for example. The next best step is to ask your leads to sign up for your email list. You can get them to sign up by offering something for free, such as a report or something useful, from your website. For instance, if you're selling wellness products, then you might offer a guide to good-for-you ingredients or recipes. This will allow you to communicate with your prospects and provide valuable information related to your business and the general field that it's in, such as special sales, events, news, and research—and stay top-of-mind to your past, current, and possible future customers. Just be sure that you're following the laws and regulations regarding email marketing.
As a last resort, you could try cold calling by phone. This is probably the most depressing and soul destroying activity on the planet. Even if you get past the usual questions such as ‘If you’re selling something – I’m not interested’ and ‘How did you get my number?’ you need a really slick and professional script and the ability to recognize and avoid lonely old ladies who just want to interact with someone, anyone, in fact.