The first method is to weave in your personal touch in your sales message. Nobody wants to be sold to by a total stranger, but many people will buy what their close friends recommend to them. If you can convince your audience that you are a personal friend who has their best interest at heart, they will be convinced to buy your products. Remember to speak to an individual in your sales letter, not to your whole audience.
Use visual representations for the problems and solutions that your product offers. Not everyone will read your text copy from the head to the tail, but most people will pay attention to images on your website. Offer quality bonuses to accompany the product. When you offer bonuses that complement your product, your prospects will feel it's a very good deal and it would be stupid to miss it. Be sure to state the monetary value of your bonuses so that people will be even more compelled to grab your good bargain.
Lastly, ask for the sale! Many people entice their prospects with the benefits of their product, sell to them with stories of how it has solved many problems, even offered killer bonuses but forget to ask for the sale. Give a clear instruction on how to buy your product (e.g. "click the button to buy now!").