I talk a lot about how being clear about your goals and purpose can help you overcome so many problems. It is, however, a problem, if you're unsure how to gain that clarity.
The first thing you need to do is create an opportunity for yourself where you can get quiet and be undisturbed. Depending on what your life is like, this can be a challenge all by itself! Keep some paper and a pen close by to help you clear your mind and record any unexpected thoughts.
Once you're in this quiet, clear space, it's time to quiet and clear your mind. One of the most effective ways to do this is to take one of your pieces of paper and write it all down. This is commonly referred to as a brain dump and it is immensely helpful. Get out every thought that you have in your head, no matter how seemingly insignificant. Writing these things down allows your mind to feel as though you have addressed them and so you no longer have the need to retain them in your head. Continue releasing thoughts until you feel a calm, clear mind.
Now that your mind has been quieted, sit in the silence for awhile. Enjoy the quiet until you settle into yourself and feel centered. You'll notice this when you feel completely at ease with life. Nothing is tugging at you, bothering or annoying you.
This feeling of being centered is the goal. When you're centered, you are best able to filter out the good things from the best things. When you're centered, you have clarity around your goals, purpose, and the vision that you have for your life.
When you're centered, you're fully in alignment with your true goals and purpose.
This is the place from which you can make your best decisions. It sounds like a simple process, but it make take some practice and getting used to. However, the more you practice, the easier it will be to get centered when the need arises!