Learn to laugh, at yourself and with each other,no matter how bad things look there is always something to laugh about.
When you have children make time for yourselves,the best thing my husband and I did for our marriage was taking a weekend for US once in a while when our children were growing up. It doesn't have to be a weekend == an hour, a date night, a long walk but take the time to focus on each other. This must have worked== we were married 51 years July 1.