Writing is a form of thinking. Use writing as a tool to clear your mind and gain clarity. Write simply without manufactured complexity. Writing will challenge your ideas and thoughts better than vague gesturing during verbal conversations. Writing forces you to confront your actual beliefs and your ability to convey them. Sometimes you will be absolutely nowhere.
Write digitally or by hand. It does not matter. Any scrap piece of paper or notebook is fine. Do not get trapped attempting to over-optimize tools.