Routine has its place in a busy life, but the danger is that the routine will become a rut, leading to boredom, laziness and sometimes to the case on the previous page, in which things are taken for granted and no one remembers to commit tiny acts of love or express gratitude.
Part of the trick to overcoming routine is to plan ahead, and part of it is being spontaneous. You'll need to plan for a date with your partner: Make the dinner reservations, schedule the babysitter and pick out your outfit. Even so, there are ways to introduce something new into your plan. Try a new restaurant, wear a color you don't normally wear or undo one more button on that favorite top you always wear.
Planning sex on a schedule can be either a boon or a hindrance to passion, so try making a date for sex, but also be open to finding ways to make sex happen if the mood strikes. If sex has become a lower priority, reprioritize! As Dr. Phil says, "Use it or lose it."
Being open to inspiration is the key to spontaneity. A shoulder rub while watching a movie is relaxing and might inspire lusty thoughts about what to do when the movie ends. Saying "I love you" (ideally followed by a kiss) is easiest of all; you just have to open your mouth and make the sounds.