Something I believe is essential in a partnered relationship is doing new, unique, interesting things. I'm NOT referring to swinging from chandeliers, or, even "swinging". I'm referring to keeping the excitement alive, just as you did when you were dating. When you're dining out, don't look at the cell phone; in fact, turn the cell phone off. Whether you are a man or a woman, don't just dress for the occasion, dress for your woman or man--clean, pressed clothing. Give surprise gifts, either out-of-the-blue, or, to mark past events (anniversaries are the first thing that might come to mind, but what's wrong with a monthly special date?). A spontaneous overnight in Bucks Cty, Center City, etc.? Or, after dinner, head to your local coffee house and have a special cup of "brew" together; see a movie in the middle of the week and treat your "date" to the big cup of buttered popcorn. How long has it been since the two of you have gone bowling? Some of them even have dining opportunities; however, I use the word, dining, lightly. Go to a venue that has the kind of music you both enjoy. Have you ever been to Melalani, Steel City or Mermaid? Take an evening or weekend class together (MALT, adult regional High Schools, TU Adult Learning, etc.) and learn something new together.
The point is: Keep it Fun, Silly, Spontaneous.
I would like to add here that I am well-aware that there are trying times that all relationships must endure: Personal and family illnesses, death of a loved one, financial burdens that come out-of-the-blue. Of course, they have to be dealt with, as these are unavoidable facts of life. But that doesn't mean that you can't pick up where you left off before those challenging times occurred.
Remember the fun you had when you were dating? Keep on, Keep on...dating, that is!
Addendum: Check out "30 Lessons for Loving", advice from the wisest Americans on love, relationships and marriage, by Karl Pillemer, Ph.D., 2015