Something we don't think much about is that while we are busy arguing and not hugging and kissing each other in a marriage, we are showing our children what a marriage is supposed to look like. Modeling a marriage is incredibly important and how you need to do that is something you and your spouse have to be on the same page about.
When my husband and I got engaged, we started talking a lot about this. We knew that we wanted our kids to hear us argue, but also resolve it in front of them. We wanted to hug and hold hands in front of them so they can see good examples of affection. We wanted to talk about finances in front of them (to some extent) so as to not set unreasonable expectations and to know there are limits on things. We wanted to pray together so they could see how it should be. We wanted to volunteer and serve together to set the example for what they should do. We wanted to show them the important things rather than the material things that just don't matter. We are not always great at these things, but we try.
Just remembering that little eyes and ears are on you can help keep ourselves accountable to the things we do and say to each other. You have to strive and show your kids what a loving and Godly marriage should look like, even though it's not always easy at times.