Read the brief given to you or a brief that you have.
From it extract all of the different product design factors (Remember VLUMPIEST)
Write on a sheet of paper (or document) the product design factors, then write the different constraints and considerations regarding the different product design factors underneath the headings.
It can make your life easier to use colour codes to help make it easier to understand.
Page 140 of Text Book
Page 154-155 Workbook