You know those WWJD (What Would Jesus Do) brackets? .. I have one that says WDIM. 
“What Does It Matter?” 

One of the secrets to having a positive relationship is to continually ask yourself, “does this really matter?”
Like for instance: 
Maybe your partner grew up squeezing the tube of toothpaste from the middle like some kind of monster.. and you roll it neatly from the bottom (like Jesus probably did). It bugs you that your partner doesn’t do it “right”, right?
What does it matter? 
Obviously you wish your partner would do it your way, it makes you mad and triggers negative thoughts. I get it. Now drop the emotion for a second and ask yourself, does this toothpaste tube tension really matter? Of course not. Do you have a preference? Absolutely! And your preference is right to you, but it doesn’t really matter in the broader scope of your relationship. This is all about “choosing your battles.” Does this frustration meet the Top-10 list of things you want to continuously battle over? 
The truth is, there’s just not enough time to care so deeply about every little frustration. When little things are making you angry, you won’t have room for positive. The truth is: You didn’t marry a perfect person, and your partner didn’t either. 
Things will bug you and you need to stop and ask yourself, “does this really matter?” 
Note: addictions, neglect, abuse, unkindness, are things that absolutely should matter! but if you keep asking, “WDIM” to all of the little things - you’ll find yourself engaging in fewer battles, and enjoying more peace.