Roy Peter Clark, a senior scholar at the Poynter Institute, describes writers like me when he says that when we’re not writing, we are often doubting ourselves. We feel bad. Instead, we could think of this period of delay as something constructive. We could reframe it as rehearsal. Just as rehearsing lines for a play is a necessary step in getting ready to perform a play, rehearsing what you are going to write prepares you for writing. Thinking, gathering information, making notes, asking yourself questions, outlining. . . all of these ways of rehearsing can help you perform the act of writing.
Clark, Roy Peter. Writing Tools: 55 Essential Strategies For Every Writer, 10th Anniversary Edition. Little Brown Spark, 2016, p. 200.