My wife and I have crossed the one-year threshold; after achieving this milestone, she told me, "Once we get past a year, we're set for life, right?"
Christmas 2011: I'm trying to look normal, I think. Didn't work.
While it's not true that strengthening the marriage bond gets easier over time (it's always a challenge—but in the best possible way!), it is true that seemingly-insignificant things (like doing the dishes, emptying the trash, and saying daily prayers) we do in our marriage help a lot.
Our faith, for instance, needs constant attention and care. We have already had periods in our married life where we've fallen short of our committment to pray the Rosary daily, or to attend daily Mass more often. We continually struggle to make faith a priority in our relationship. But we push through, and keep on getting back into good habits of prayer—together as often as possible.
Keeping up with chores is another area where routine is important, but often done haphazardly. We have a wonderful chore spreadsheet, and we often go on 'cleaning rampages' where we complete a bunch of chores in a day (well, that's more me than my wife... she usually does her chores regularly), but we also skip chores some weeks due to a busy schedule. We're not living in a dump, and nothing is unsanitary, but things tend to go downhill quickly once you let the routines slip away too far.
Routines may sound boring, but they are important for a strong relationship.
Giving a kiss or hug and saying 'goodbye' every time we depart each other's company helps us remember that we are always looking forward to seeing each other again soon. Going to Sunday morning Mass together, even when one of us is really tired, or would like to sleep in, reminds us that we need to approach our relationship with God hand-in-hand. Watching a movie or reading together on a regular basis lets us learn to relax together (of course, too much media consumption can be harmful!).
These routines firm up the foundation of our married relationship. Some of the routines will change over time—especially when children enter the family—but many will be a stable bedrock of our marriage for the rest of our lives. If we let them slip away, we risk losing an important part of our love for one another. The covenant we entered more than a year ago is important enough that we are both vigilant about the 'routine' of loving each other.