Creating a physical product is much more different than creating a digital one.
Involved in the creation there are countless different things.
For a cosmetic, for example, we have to take into consideration the consistency given a specific temperature, how similar to a cream it is, the ingredients, and so on.
Also, you have to create your own beta-test of the product to avoid any production issue.
Beta testing a physical product is helpful to determine if you got something wrong.
But the main joy of creating a product of this kind is the pleasure you have when it’s finished.