Number 4 was attractive to me. "What happened next?" - surely motivates in writing more & more.
About routine - it always sounds good. In fact, routine helps a lot in many aspects. But alas! Breaking routine is a routine to me for many years! I wish to get rid of it, yet I can't!
Late night writing is proven superb to me. After awaken from sleep, mind in that solitary time remains so fresh & creative that my inner muse starts playing fluently. Interested ones may have a try. The only pre-requisite - have to go to bed early. Can't get asleep at that early time? No problem, make a long walk for about one or two hours in afternoon. And see how sleep grips you early!