This is an excellent video diving deep into creating a product prototype. This is part of a larger series that applies to all parts of creating a physical product. I use this video for students creating both physical products and services because it shows how you think through what they need to do to create a service as well.
This is an amazing video describing the process a designer took to design a smart watch. I use this video because it clearly states upfront what his goals were, how he tried several approaches, and what he did to test his ideas. Whether students are creating a product or a service, this video is helpful for them to see how ideas come to life.
The engineering design process is the process anyone who creates a physical product will use to create their first version of their design. This page provides example projects they can complete in addition to giving all the information needed to design their own ideas.
While there are many different ways you could go about creating a new product, I typically use this 6 step process with my students. It is framed from the perspective of a lesson plan and advice from the teacher who designed the unit.
This simple lesson plan on design thinking takes students through an activity to build a better candy bag. Activities like this can help younger students who aren't as independent yet at completing projects, or the subject matter could easily be swapped out for a product that appeals more to older students.