Step 1: Find 3 things to complement your partner on every day.
Step 2: A few times a week, ask your partner how they are feeling.
Step 3: Spend at least 1 day a week apart from each other.
This shows a few things. The first is that you see them in a positive way, the second is that you have a genuine concern for their well being, and the third is that you need time to yourself to avoid bickering about stupid things. I will try to implement this and see how it works.