Consequentialist Theories: What would you do?

When I began reading the handout on Moral Philosophy, I came across two interesting aspects on consequential theories ( a chosen outcome based on our decisions of our own actions). One is Egoism, which is basically performing an action that will benefit oneself; versus Utilitarianism, which means performing an action that will benefit the greatest good for the greatest number of people. Both theories have good intentions, but when it comes down to the question of right or wrong, what does one believe? How does one's morals shape decisions to be made in a given situation, such as peer pressure or sex? Everyone has different morals and aspects on life, but how often do we base our most important decisions on these consequential theories?