Organize your paperwork and research business PhD programs. Obtain your academic transcripts, saved research and letters of reference from instructors. Plan on applying to several schools, especially institutions that represent your dream school, a solid business program,and a school with accessible entrance requirements. Especially consider schools that have strong, widely-recognized departments in the specific research areas of your interest, whether finance, marketing or other subjects. Before applying, check required minimum GMAT or GRE scores.
Take the GMAT or GRE if you haven't already. Study and prepare ahead of time, if possible, with colleagues or peers. Practice on sample tests to re-familiarize yourself with standardized testing and timed testing. If the resulting scores are not high enough, decide whether to re-take the test for a better chance at acceptance into your desired business PhD program.
Submit your completed application to the schools of your choice (see references below) along with required paperwork, including transcripts, application fees, statements of financial viability, letters of recommendation, statements of intent and GMAT/GRE scores. Be articulate about the area of specialization in which you desire further research.
Write thank-you correspondence to letter of reference contributors upon acceptance into a program, communicating the contribution their efforts made in the process.