Get good grades. Cultivate relationships to secure good recommendations. Networking is more important at advanced levels. With the time, expense and energy needed to complete a graduate degree, you should carefully contemplate before embarking. You will need to stay motivated to keep up with the demands of graduate life including maintaining at least a 3.0 GPA, as most programs require.
Graduate schools expect high initiative and self-discipline from students.
Talk to alumni, professors and those in your intended field of study. You are on the right track if you can't imagine being any other field. Without advanced credentials, an otherwise advancing career in some fields may be thwarted. Unlike a few decades ago, a successful career path is the responsibility of the employee not the employer. An added degree can influence how far and fast you can progress in your career.