In this post Christian Schormann talks about SketchFlow as a way to explore and “mind map” ideas
without having to think about UI details earlier than you need to.
This “mind map” aspect always is an important aspect for me in
designing UX – I like to think about the abstract flow, navigation and
composition (in other words, the structure) of a design first, without
immediately thinking in terms of concrete UI, controls and layouts.
Early on, it often does not matter much which exact widget you use to
navigate or interact.