From Designing Interfaces:
When doing design, a sound process is critical. You need to have certain elements in a design process:
Field research, to find out what the intended users are like and what they already do
Goal and task analysis, to describe and clarify what users will do with what you’re building
Design models, such as personas (models of users), scenarios (models of common tasks and situations), and prototypes (models of the interface itself)
Empirical testing of the design at various points during development, like usability testing and in situ observations of the design used by real users
Enough time to iterate over several versions of the design, because you won’t get it right the first time
I like the language and tone of this book. And the approach taken to identify patterns of interaction and documenting them. It is now in my Safari bookshelf (reading list). Will post more as I go through it.