What is the best way to market your product?

It depends on your product, but almost every product / company can benefit from a well designed social media marketing plan. However, its not just about creating posts to promote your product. Instead, offer value to your audience in your posts. Incorporate trends into your brand's / product's style. In return you will grow a bigger following that has a higher trust for your brand, ultimately converting to more sales in the long run. Stay engaged in communities that align with your brand, this will also build exposure and trust. Aside from social media, email marketing can be very powerful when done correctly. There are a variety of other ways to market your product / brand, it just depends on your target and who you are trying to speak to.