Invest in quality -- this seems obvious. In practice, it's strikingly the exception. Look at how much low quality everything surrounds us. Living a rich life involves discerning between the ubiquitous low quality and the rare high quality. We all know to make quality financial investments, but the principle applies to many other aspects of life. Generally speaking, quality costs more, but it's almost always worth it. Quality lasts. It rewards you. The higher cost is actually a good thing. It requires one to think about whether she wants to make the investment. This results in a disciplined, more deliberate life.
Whether it be material goods, people, experiences, thoughts, or how one spends his time, the focus needs to be on quality. By investing time and emotion in good, virtuous people, you will have great relationships. By investing your leisure time in improving yourself, you will have a better life. There are countless examples of this and it is highly individual.
When faced with the choice, choose quality. You may have fewer, but you will have better.