They look for strong students who know what they want in their field. Research is valued as well as internships. Evaluations and strong grades play a major role, also high GRE's help but do not make or break you. Graduate schools use grades as a dividing line, high grades show strong study skills. A GPA of 3.00 is standard.
Psychology has a strong liberal arts background and is a good start for other fields.
Make sure you take the correct prerequisite for that particiular field. Thanks for your letter of March 30. After careful consideration, I regret to inform you that I am unable to accept your rejection at this time. This year I have been particularly fortunate in receiving an unusually large number of rejection letters. With such a varied and promising field of schools, it is impossible for me to accept all refusals.