Count your blessings — but not everyday. Sonja Lyubomirsky, an experimental psychologist at UC Riverside, found that people who once a week wrote down five things they were grateful for were happier than those who did it three times a week. "It's an issue of timing or frequency," says Lyubomirsky, "When people do anything too often it loses the freshness and meaning. You need to have optimal timing." Lyubomirsky added that it has to feel right. She tried to count her blessings and hated it. "I found it hokey. It didn't work for me. Just like a diet program, what you do has to fit your lifestyle, personality and goals." In essence, gratitude might not be for everyone. But if it is, another exercise is to think of a person who has been kind to you that you've wanted to thank — a teacher, mentor or parent — and write a letter, once a week to different individuals over two months. You don't even have to send it to feel happier.