Hi Oli, I think with Amazon you just have to pick products that have quite a high price from the start. Me with my beach decor site, most home decor items are fairly cheap to buy, so the commission is not that great. You either have to sell heaps of cheaper products (which is very hard) or some expensive products (which I am not sure will be easy, either).
Giving away a free informational product such as an e-book, an email series or a mini-course is a popular tactic many affiliate marketers use. Usually, your readers will have to provide their email addresses to receive the product from you. You can then use this to sell to them via email marketing. Additionally, an informational product can generate interest in the actual product you're trying to sell. If your product is popular enough and brings enough traffic to your site, you could also monetize the traffic in other ways, such as AdSense.