Most likely, no writer will use all of these prewriting activities, but using at least a few of these techniques can make it much easier to begin writing an essay. People who sit down to a blank screen and cannot understand why an essay is not just flowing onto the page probably have left out some important steps in the writing process.
After John had finished with his prewriting activities, he feels confident that he will be able to start writing a draft of an essay, so John begins the drafting process.