My wife and I find that spending time together makes a big difference. For me, if I spend about 5 hours quality time a week with her, I feel a LOT closer to her. Hiking, sailing, even just driving around in the car and talking all qualify.
But we each have our own private hobbies and lives that are quite distinct. In fact, she has a job in the court system in which almost everything she does is extremely confidential, so it's hard to even talk about it.
