If you have a propensity for writing and you can slay with your prose, consider writing an ebook. While the market has certainly become saturated as of late, books that help teach people about a technical topic still sell extremely well. This is a great source of passive income but does require a large amount of effort at the outset before any money is generated.
Once you have the affiliate links you need, it is time to present them to your audience. As you start using affiliate marketing to talk about products, you need to be aware of how your audience perceives you. If your website appears to be only after their money through an overwhelming amount of affiliate links, then they are more likely to simply leave your site.