Spend time in reflection every day

Once you improved your capacity to focus, it's time to practice reflecting on your life.
As trite as it may sound, you have to know yourself. If you want to be able to live your life fully, you must know your principles, your values, and what makes you tick. And above all, abide by them.

Happiness is not attained by procuration of mental pleasure or material possessions. It is attained by a conduct in accord with one's principles.
And the only way to live and act according to your principles is to reflect on your conduct: what you have done, what you're doing, and what you're about to do.

This self-examination, which is best done daily, enables you to use your mind to push you higher, instead of having it use you. We like to think reason has the biggest share in our lives but truth is, we almost always act instinctively. That's why it's even more important to regularly think about your conduct and your principles, re-assess, and reflect on them.
Use your reason to determine if you live true to your principles and values, or if you're failing to do so.

Look hard at yourself in the mirror, no matter what image is reflected to you.

The best time to spend in reflection is in the evening, after the day's work. But any time can work, the important thing is to do it daily.

References

How To Live 24 Hours a Day - Chapter 9 - The Reflective Mood