How to make a decision based on Buddhist principles? I have been practicing Buddhism since a child, about twenty years.  Throughout my adult life I have been trying to combine my practical life with my Buddhist beliefs.  In some situations, however, I am not seeing how Buddhist principles apply to decision making.  For example, how do I apply Buddhist ideals in deciding which college to go to, what profession to do, and what job opportunity to pursue?  These are the mundane but unavoidable decisions for the layman.  Of course, I'd not pursue a career in military or defense industry due to my beliefs, but there's not always a clear choice between other professions, jobs, etc based on Buddhist beliefs.
A book by Bhikkhu Basnagoda Rahula, Ph.D entitled The Buddha's Teachings on Prosperity At Home, At Work, and in the World devotes a chapter to "The Buddha's View on Decision Making".


  I have seen no other cause than the presence of false views to block the origination of right thoughts in the mind and to corrupt the right thoughts already present in the mind. I have seen no other cause than the presence of correct view to inspire the right thoughts already present in the mind. ~ The Buddha, The Numerical Discourses


Venerable Dr. Rahula, outlines 10 kinds of fallacies in reasoning (from several suttas including the Kalama, Bhaddiya, Canki and others) that if one were to believe to be true could create such false view. 

Fallacy 1. Reported information is true 
Fallacy 2. Traditional values, beliefs, and practices are actual truths
Fallacy 3. Social truths are actual truths
Fallacy 4. The texts are true
Fallacy 5. Logical reasoning is always correct
Fallacy 6. Reasoning based on imagination and speculation is correct
Fallacy 7. Hypothesized reasoning is correct
Fallacy 8. One should accept a view because it is compatible with one's own way of thinking.
Fallacy 9. One's persuasive skill validates the message
Fallacy 10. Individual authority is a dependable criterion for making decisions

Each of the fallacies is explained in detail and the following chapter details "Correct Reasoning, Right Decisions".


  If you understand that this action is right, harmless, blissful, beneficial, and admirable, take that action and follow it. ~ The Buddha, The Numerical Discourses


The four forms of correct evaluation (from the Kalama Sutta) are:

Right Evaluation 1. Wrong motivations lead to wrong decisions 
Right Evaluation 2. Absence of wrong motivation leads to right decisions
Right Evaluation 3. Consequences of a decision make it right or wrong
Right Evaluation 4. Attention to the views of qualified people lead to right decisions.

In summary, the Buddha spoke of the correct way to make decisions on many occasions. Due to the way discourses are categorized, it's not easy for the average person to pick out the teachings of the Buddha on such practical matters in any sort of an easy way. This book has done that and combines an easy to read style with the expected references to the suttas from which the information is taken. It's available from Wisdom Publications if you are interested in reading it in full.