The Cross-sell products option provides an opportunity to sell additional products usually bought with the selected product, however, you can add any product from your catalog even non-complementary to the product in the cart. Cross-sells are displayed at the bottom of the checkout page. For example, when customers buy a T-shirt, they might also want to purchase a mug.

1. Go to Catalog > Products > Manage Products.

2. Click Edit for the desired product.
3. Click the Cross-sells tab.

4. Click Add new cross-sell product.

5. Check the products you wish to add as cross-sells.
6. Click Save.
7. Click the Save button.