Step 1) Find products that people really want, many of the affiliate marketers simply promote products that people do not want.
So find out what people want.
Step 2) pinterest is a visual platform, so infographics work very well. Research the product you want to promote
Find the key features and hire someone to create an infographic with pictures of the products and some key features.
Create not just 1 infographic, but 4 that have a different angle for this product. Each infographic can have different color schemes, so you can attract different people for the same product.
I hope it helps