First, yes a sense of humor helps especially in the later years. In fact, the first thing that sold me on Mom was the very first sight of her when she came around the corner of a building with her friend. They were laughing and happy as could be, I never even noticed the other girl, I was sold on Mom. She was a total package of everything I ever wanted even though I had not thought much about what I wanted in a girl. The laughter and happiness was the frosting on the cake. So always remember to look for the thing that first sold you on your partner.
When something they say or do rankles, try to remember something good about what they do or are. If that fails, remember how good they feel when you make up after an argument.
There tons more stuff but those will get you started. My defensive driving class brought another thought to mind. It can all end in a second thru accident or heart attack, so never waste any seconds. in my battle against impatience, I have found it takes a lot less energy to be happy than angry plus you get to enjoy living more. Enough already!