Wow, that's a tough question. I'll try and see if Sonya has time to answer this question. We're not as seasoned as some but I can honestly say I'm happily married after 11 years of marriage.
If I had to state that there was a "rough" period of our marriage then it was the first 3 years. That was exacerbated by:
1. Getting accustomed to married life.
2. Me being a jerk a lot.
3. Going to a Church with poor doctrine.
4. Moving thousands of miles from her family 3 months after marriage.
With all that, however, I can honestly say that I have never been unhappily married. I can't think of a time. I've always felt blessed to be married to my wife.
We are still certainly improving but here are a few important things:
1. Arguments for the man usually center around winning the point at issue. Arguments for women usually center around how she feels about the thing and how you made her feel. I've spent countless hours chasing a point she didn't really care about. She cared about how I made her feel and whether or not I could acknowledge that.
2. Thus, if you begin to argue, start to listen for cues that she is trying to get you to see that you made her feel a certain way. Acknowledge how your language or attitude produced that and then, gently, you can make the point that you were trying to make.
3. If you end up in corners and angry at one another, do not let the sun go down on your anger. Be the leader and repent first. Practice repenting when you absolutely do not want to do it and you're convinced (sinfully so) that she ought to be the one that repents first this time. Lead in the area of repentance.
4. Your wife needs to train herself in the art of being quiet when you're being a jerk. If she lets you vent and does not answer your anger with words but sits silent then you will be convicted and will repent and restore fellowship. Paul wasn't kidding when he said that women can win their husbands with quiet, Godly submission. It heaps coals of fire on your head.
5. Your wife will go a long way if she learns how to treat you with respect even in the most difficult times. I cannot explain why we need it but it is commanded of a wife to her husband to meet a need. It is the source of much frustration and sin when wives treat their husbands with disrespect.
6. Above all, love your wife. That's harder than it sounds even though it is so fundamental. Love her with warmth. Be tender-hearted and gentle to her as a duty, even when it is not the thing you want to do. Love her as Christ loves the Church - that is to love her in a way she does not deserve. Love her in a way that is sacrificial. And when you do not for you will not (because it is by grace) then repent of your sinful lack of love for your wife and continually go to the throne of grace for forgiveness and the Gospel strength to be a good husband.