A popular way of designing, and probably rightly so, is the user centered design strategy.
Simply put, the design process is to some extend dictated by what the end user would like the product to be like, what the user thinks the products should have of functions, and to some extent what the design could look like.
There are many ways of designing with the user as the core of the design process. Some examples are: the questionaire, surveys, user registrations, interviews, etc.
After an initial research into what the user would like, a popular tool is the use of Personas.
Personas are fictional characters, that are created to represent different user types. They are given a set of attitudes and behaviors, and the design is viewed throgh these characters. The use of personas are only one tool, and can not stand alone, but they can be quite effective in the user centered design phases, when time is limiting the acces to user groups. In the end, the evaluation by a focus group or group of end users can prove or disprove the assumptions made by the designer on behalf of the personas.
For my work on designing a chair for parks and public spaces in Copenhagen, I’ve begun working on a group of Personas, these are not near as detailed as they can be, nor yet finished. But they give an idea of what my intent is for the Personas.