I found this little gem at the design museum, beautiful newsprint magazine about the relationship between design and the bicycle. I think that a lot of the points made throughout this apply to all areas of design.
"the relationship between rider and designer should be an intimate one. Before even starting to sketch out ideas, the designer must start by fully understanding the challenges the rider will face and become intensely familiar with the environment in which the machine will be used. Only through listening intensely to the user and amass in personal experience in the field can they strike the right balance between performance, reliability and usability. For me, design should be 50% facts and 50% art." - Chris Boardman