It is usually not feasible to wait for an entire day in which you have nothing to do but write. In order to make the most of the time you have available, try using quick start techniques. For example, once you've finished a section or a paragraph, write the first sentence of the next one, or jot down clear notes about what you want to say next. That way, you'll be able to pick up right where you left off, instead of wasting time trying to remember what you were thinking about!