Well, since no one else is taking your request seriously...
My husband and I have just celebrated our 25th anniversary, so I feel "qualified" (yeah, right) to dispense advice. Unfortunately, one of the things I have found is that there ARE no cut-and-dried rules of a successful marriage. There are so many factors to take into consideration: individual personalities, geographics, etc. Each marriage is different, because the PEOPLE are different.
For instance: there is an old rule "never go to bed angry". That didn't work for us...all it did was make for a few very, very late nights, and the tired-er we were, the less sense our arguments made. Sometimes, going to bed angry and waking up refreshed with a clear mind made for a more rational discussion.
Another: I'm confrontational, my husband keeps things inside. We REALLY had to find a middle ground on communication on that one!
Yet another: Some couples need to be together a lot...others desperately need "me alone" time.
I think the most important piece of die-hard, tried-and-true advice is to completely keep God in the center of all you do. Pray together.
However, to me, the absolute #1 thing is: COMMUNICATE! This is of utmost importance, whether it be about the news, the families, sex, education, children, movies, books...Keeping an open line of communication is paramount (second to the above Keeping God In, of course).