How to mitigate or minimize quarrels between husband and wife, especially on small issues?

Tolerance is key, I feel. Identify the negative aspects of your partner's habits/traits and accept them with tolerance if they are minor. For example, I am a neat freak and I hate dirty dishes in the sink but my fiancé has a habit of leaving them to sit instead of washing them immediately. Nagging solved the problem for a while but it's not permanent. I used to get sooo annoyed with this but I realise that I shouldn't sweat the small stuff because it's just not worth it. So these days, I let it pass. A few dirty dishes shouldn't ruin anyone's day.