You can maintain your relationship just by keeping your nose clean and being there. You can really boost the quality of your relationship by learning to communicate effectively with your spouse. The trick is to acknowledge this fact: The average married couple spends less than 10 minutes a day engaged in stimulating conversation. Most communication between spouses revolves around the same subjects on a daily basis. These typical topics are money, work, schedules, children's school and schedules.
Try to dream with your spouse. If you don't know how to do that try simply offering what you'd like to be doing with your spouse 1 year from now. This could be wind surfing in Hawaii, spelunking in the caves and grottos of Bermuda or parasailing in Key West. Your challenge is to talk about something other than the normal and then of course be quiet and let your spouse voice his/her ideas.
If you value this relationship and feel it is a forever thing then you need to treat it as such and engage your spouse or partner in thinking that conveys that you see yourself with this person for years to come.