Techniques that made Steve Jobs, Richard Branson, and Charles Schwab feel better are guaranteed to work for you too.

Seeing Steve Jobs‘s life slip away was breathtaking, but the lessons offered can be life changing. It struck me as strange that I’d never seen him happier more often than in his last decade, which arguably was his hardest health-wise and yet his most successful professionally, as he transformed four different industries.

I started to notice practices that he embraced that enhanced and lengthened his life. The cynic in me would have considered these too Pollyanna-ish had it been anyone else. What the world’s great entrepreneurs know that most people don’t is that optimism isn’t naive, it’s more productive. Steve didn’t succeed on pessimism, so why should any of us indulge exclusively in our brains’ natural catastrophic bent toward depression?

It’s seductive to think that the bad news we get every day is the whole truth, when, in practice, negativity tends to help us indulge in the luxury of tolerating learned helplessness. Why make the effort to intervene when it’s hopeless? But that’s quite the opposite of the action-oriented mindset of entrepreneurs, whose attitude is tilted more toward the audacity of believing we can actually have impact and make things better if we think different.

1. What Worked for You Today, and Why?

What that means for you tonight, as you head to bed, is that you need to not only understand what went wrong, but finish your day practicing the skill of thinking about what worked and why. This first principle was something that worked for Steve and comes from positive psychologist Martin Seligman, who, with the University of Pennsylvania, conducted ground-breaking research into changes in life-satisfaction and depression levels that have been validated in random-assignment, placebo-controlled experiments.

“It makes sense to analyze bad events, so that we can learn from them and avoid them in the future,” Seligman says. “For sound evolutionary reasons, most of us are not nearly as good at dwelling on good events as we are at analyzing bad events. Those of our ancestors who spent a lot of time basking in the sunshine of good events, when they should have been preparing for disaster, did not survive the Ice Age. So to overcome our brains’ natural catastrophic bent, we need to work on and practice this skill of thinking about what went well.”

The truth is that primitive people who welcomed the good news, while also re-engineering their communities to work better collaboratively, lived the longest because they had a strategy to defend against or avoid tomorrow’s disasters and prosper over the rest of the animal kingdom.

The problem with our primal, reptilian habit of perpetual pessimism in a modern world is that we’re rehearsing doom. That impulse ironically could help us become more effective at repeating the nasty episode, rather than being optimistically strategic about the future. At best, the bad news increases anxiety, doesn’t prepare you for better days, and doesn’t make you fun or attractive to people around you.

Here’s a better practice: “Every night for the next week, set aside 10 minutes before you go to sleep,” Seligman advises. “Write down three things that went well today, and why they went well. You may use a journal or your computer to write about the events, but it is important that you have a physical record of what you wrote. The three things need not be earthshaking in importance.”

Write down why those three good things happened. For example, when I wrote down that a close friend referred a great customer to me, it was important to make a note that it happened because I often remember to call him with good news and referrals. It may seem silly at first, but it has been easier for me to focus on a positive insight like this one than it has been for me to practice meditation as regularly as I should. This procedure has the added benefit of being useful at a practical level, because it gives me something I can actually do to achieve better results again tomorrow.

I’ve found this is a helpful habit to build in our personal lives, too. While friends and family resisted it at first, it’s clear we never were hesitant with complaints! The inverse was much more rewarding, and what a refreshing twist to have people you care about actually go out of their way to say something constructive. By the way, these ideas and a lot more are available in Seligman’s book, Flourish: A Visionary New Understanding of Happiness and Well-Being, which is well worth keeping on your e-reader.

2. Who Helped You Be Successful Today, and Why?

A second practice that pays incredible dividends is to write a testimonial to someone every week. It’s not something Steve Jobs did, but I’m grateful to see it all the time with world-class thought leaders, like former Ford CEO Alan Mulally and No. 1 executive coach (and bestselling author of Triggers) Marshall Goldsmith, whose encouraging emails warm my heart and frankly help me stay on course and do more than I ever imagined. And I’ll never throw away the sweet notes I’ve received from my friend and mentor Richard Branson (who recently also wrote a heartwarming note to his new grandkids) or my former boss, Charles “Chuck” Schwab, who always knew intuitively how writing an authentic note–that simple act–could permanently improve and energize relationships. When I’m gone, those notes will still be there on my desk.

On a personal level, imagine the impact it can have when a father sends a fact-based (not fluffy) endorsement to his teenager daughter for all the ways that she inspires him, or a son sends a thank you note to mom for real stuff she did for you?

Surely you haven’t achieved what you have in your life and career all by yourself!> In my research project on how people become more valued, respected, and admired for what they do, we asked high-achieving executive coaching clients to remember all the people who make them successful. (You can find a copy of the research in Admired: 21 Ways to Double Your Value, a book I co-wrote with my wife, Bonita S. Thompson.)

Here’s how it works, in Seligman’s words: “Close your eyes. Call up the face of someone still alive who, years ago, did something or said something that changed your life for the better. [Thank] someone who you never properly thanked; someone you could meet face-to-face next week. Got a face? Your task is to write a letter of gratitude to this individual and (if possible) deliver it in person. The letter should be concrete and about 300 words: Be specific about what she did for you and how it affected your life. Let her know what you are doing now, and mention how you often remember what she did. Make it sing! Once you have written the testimonial, call the person and tell her you’d like to visit her, but be vague about the purpose of the meeting; this exercise is much more fun when it is a surprise. When you meet her, take your time reading your letter.”

Do it now. “When we feel gratitude, we benefit from the pleasant memory of a positive event in our life,” Seligman predicts with virtually certainty. “Also, when we express our gratitude to others, we strengthen our relationship with them. But sometimes our thank you is said so casually or quickly that it is nearly meaningless.” This exercise gives you a “do-over” of epic proportions, and makes it incredibly hard to be depressed that day.

The bottom line is that highly effective leaders focus on what they’re for, rather than what they’re against. When you do that at home and work, you’ll get more done, feel richer, and, yes, you’ll even sleep better!