This is the most common cross-selling strategy. As you can see, it consists in offering products that are complementary or similar to the one presented in the product page.
In the context of a home décor store, for example, we can imagine a client visiting the product page for a cushion. The similar products offered will be products that fulfill the same need. In this case, we will present them other cushions, at similar prices, that could make them want to buy.