Rosh Hashanah is the Jewish new year, the time when we think about our past year and plan for our next. What do I want to repeat? What do I want to do differently?

I usually start with everything I want to do differently. And the list is long.

I eat way too much — well past my point of being full — and leave almost every meal uncomfortable. I feel scattered in my day, focusing on too many things at once, switching rapidly from one thing to the next. I react to what's in front of me too often rather than making strategic choices about where to spend my time. I treat many of my relationships more as transactions than deep connections, appreciating people for what they do for me rather than who they are. In fact, I treat myself that way too, valuing myself for my performance more than my existence. My writing has felt more rushed lately as I produce more and enjoy less. I won't bore you with the rest, but I assure you there's more.

Normally, I would do what we usually do in the business world: develop a long list of things to do to correct these problems, a series of development plans to improve my performance in each area. I'd learn about new diets, tell myself to stop multitasking, create a plan for improving each one of my relationships, cordon off more time for writing, and so on.

But here's the problem with development plans: They're overwhelming and disconnected. By the end, I'd have ten different plans for ten different things I want to change, and I'd make little headway in each. It's just too much — too hard to act on and to easy to abandon.

As I looked at my list last year, I noticed the theme: I'm moving too fast.

I realized that pursuing an individual development plan for each thing I wanted to fix would only worsen the problem. I needed to reduce the complexity, not add to it.

So I came up with a single idea that would positively impact everything I wanted to change.

My theme? Slow down.

My thought was that if I focused only on that, everything else would improve.

And, so far, it has. When I started eating more slowly, my meals effortlessly shifted from three courses to one, and I'm enjoying the food more. Once I slowed down in my conversations, I found myself listening more, talking less, caring more deeply, and enjoying each person more fully.

And what I thought would be a downside has actually been a positive: Slowing down has meant that I can't get as much done. Which has forced me to make strategic choices about what to spend my time on and what to ignore. I'm more thoughtful, less scattered, and enjoying my work more fully. Counter-intuitively, I'm more productive.

What's nice about a single theme is that it's easy to implement, simple to remember, achievable and sustainable. It's just one thing.

So what's your one thing? After thinking about the best of who you are and what you've done, list the things you want to change. Then, stare at the list until it reveals the one thing that would impact it the most. Maybe, for you, it's being more aggressive. Or less. Maybe it's slowing down or speeding up or speaking out or being more gentle with yourself and others. If you're not sure, try something for a few weeks and see what changes.

If you are preparing for performance reviews, look for that one thing too. You'll see a greater performance improvement in yourself and your employees if you cut through the noise.

Then, each morning and at various moments throughout the day, remind yourself of your one thing. You won't need to make it your screen saver or write it on a post-it and place it on your mirror at home. It's only one thing. It will quickly become second nature as your results reinforce your commitment.

Peter Bregman is a strategic advisor to CEOs and their leadership teams. His latest book is "18 Minutes: Find Your Focus, Master Distraction, and Get the Right Things Done". This article first appeared in the Harvard Business Review. 

Peter Bregman is a strategic advisor to CEOs and their leadership teams. His latest book is 18 Minutes: Find Your Focus, Master Distraction, and Get the Right Things Done.