Be nice to your spouse or significant other. This is not only an inherently good idea, but will help you avoid the following situation, which I just read about for Wills & Estates. From 1993:
A man who was nagged by his wife to stop smoking has left her everything---but only if she takes up his habit as punishment for 40 years of "hell." Marin Cemenescu, who died last week at age 76, stipulated in his will that to inherit his house and $30,000 estate, his 63-year-old wife Aneta must smoke five cigarettes a day for the rest of her life.
"She could not stand to see me with a cigarette in my mouth, and I ended up smoking in the bathroom like a schoolboy," he wrote in his will. "My life was hell."