Create an Add-on to display with all the products in your catalog
This scenario is best suited for things like a Gift wrap add-on that needs to be displayed with all your products.
Step 1: Click on MANAGE ADD-ONS link on the home page
Step 2: Click on "Add-Ons for All Products in the Catalog" on Add-Ons page
Step 3: Click on "Add Add-On"
Step 4: In the product picker, select one more product or its variants to appear as an add-on.
Once Add-on products are selected, they will appear under ADD ONS list