I would hope you have had discussions about religious differences, whether you want children, your future aspirations in terms of finances and so on. Those are all major issues you have hopefully already ironed out.
In my experience, you shouldn’t just have discussions as a young couple, you should make tuning into each other a regular part of your lives. I would recommend finding some time every day to talk about how your day went. And really listen to your partner when you do this. For us, we share coffee/tea every morning and talk about what we have on for the day. You might find sharing a glass of wine or a coffee at the end of the day works for you. Nonetheless, set aside a time every day to just talk to each other. It’s so easy to let this slide, but I find that 30 minutes in the morning one of the best parts of my day.
I don’t really buy into this ‘never go to sleep on an argument’ stuff. In an ideal world, you will uphold that, but there will be times when your husband/or you annoy the other and you end up lying in bed fuming at the ceiling while he’s snoring next to you. That’s how it works in our house anyway. I can’t sleep when I’m angry, he has no problems! What we do do is talk about the disagreement once we’ve calmed down. We don’t just discuss the problem or issue, we discuss how we handled it. So if I was brutal (and I can be), he’ll let me know. If he was condescending (and he can be), I’ll let him know. Not in an accusatory way, but in an illuminating way. And be ready to accept your faults and to try to learn and change them. Don’t treat your partner’s feelings as not mattering. They do. Be respectful of each other. Treat each other with care and love. Cherish your relationship. Even when you’ve been together for 20 or more years.
If should say if you follow this advice, you will always have discussed things that come up – small and large issues. And you will be checking in with each other’s feelings and, I hope, laughing together and not losing touch with each other. Complacency is the killer of relationships.