To many in the western secular world the idea of living by principles will seem somewhat alien. However, many cultures of the past, and, to a degree, the present, have principles or values that are seen as important to live by.
Many of the most successful people have principles that they use to guide their decision making and how the spend their time. For example, someone who values integrity will likely stick to their word, do what they say they are going to do and make sure they are consistent on their positive habits.
As strange this concept might be for you, I recommend looking at principles in two ways. Firstly, review what you care about, what you value. Secondly, review your goals and what you want out of life. Then see where there is a cross over. For example, you might value good health and you want to achieve more at work. If you build in habits that optimise your health you will likely have more energy to put into your work. Your Principle to live by might be ‘healthy habits are productive habits.’
Try out a few principles and see what fits. You do have to commit to loving by your new principles for a while before disregarding them as a bad fit or unhelpful. Sincerely try each new habit for a month and see what happens.
The Fullfilment Project 