MiiDuu makes it easy to show your customers which products are related. When you are creating or editing a product, simply click the "Related" tab. Then select the category from the drop down menu of the product which you would like to note as related. All of the products in that category will appear in the box below. To link two products together, simply select the product and click the arrow that points to the other box. If you make a mistake, just select it again and click the arrow going the other way! You can repeat this process until all of the related products are listed in the "Related" box.

Now it's time to display the related products on your store. If the template you're using does not have the sidebar widget, you'll see the related products at the bottom of the store (see the below image).
If there is sidebar widget , just go to your layout tab and move the "Related" button into the sidebar(s) you would like it to show up in!

Afterwards, the related products will look something like this: