Dilgo Khyentse Excellent Path to Enlightenment (PDF)

When we take our first steps on the Path, we are not yet capable of helping others. To accomplish the good of others, we must first perfect ourselves, by purifying and transforming our minds. This is the aim of what we call the preliminary practices, which establish the foundations of all spiritual progress. You may feel like dispensing with these foundations in order to practice teachings that you think are more profound, but if you do so, you are building a palace on the surface of a frozen lake.

Here is an explanation of these preliminary practices. There are two parts: (1) the outer or general preliminary practices; and (2) the inner or particular (extraordinary) preliminary practices.