Hands down I’d say the best thing you can do is research 1 primary keyword, craft an enticing article title that includes your keyword (though it doesn’t have to be an exact match), spend time writing your search engine snippets (SEO titles/meta descriptions), and by far the most important is making your content as VALUABLE as possible through videos, nice graphics, table of contents, bold/colors/styling, etc. Small things like keyword density barely matter.
You can also establish commission tiers based on specific product categories. For example, you could pay 2 percent revenue share on electronics, and 10 percent on home decor, since the former carries a lower profit margin than the latter. A challenge of working with this dual structure is the technical integration. You will need to create a product feed for the affiliate network, and for each affiliate transaction that occurs you will have to submit item-level data to distinguish, say, electronics from home decor. Neither task is particularly challenging, but it does require some work.