The most important part of the design process for me in the creation of ideas. It is vital that these concepts are grounded in practicality and well rounded logic. I believe it is only common sense that all physical products are built to stand the test of time - apposed to momentary trends.
Because of this, I place a lot of time and consideration into the ideation process. I personally enjoy freehand sketching in the beginning. The process then moves to sketch models, followed by detailing the final CAD design and realising the final form through visualisation.