Invite an unusual guest to dinner. Go out of your way to think of someone whom you or your family would not expect to find at the dinner table, and invite him or her. You don't have to make anything special; your everyday cooking will do just fine. What's important is that the person is outside of your normal intimate setting, but is someone you'd either like to know better or want to thank for having been kind or generous to you.
Can you think of a particularly difficult situation with which someone recently helped you? Did someone go to bat for you on a car loan? Is there an individual with whom you regularly interact on a business level that you're itching to get to know better? Invite her for dinner. It will totally change the interaction that goes on that night at the dinner table. Everyone in your household will be more alert, will want to be on his or her best behavior to impress your guest. Your relationship with your guest will change as well.
If you dine alone, this is an opportunity to show your guest how naturally you can prepare a meal. Or if you want, you can forget about your normal dining routine and practice putting together an evening that will dazzle your visitor.— Alan Epstein in How to Be Happier Day by Day