Attend an information session, typically held twice in each semester. Talk to faculty, tutors, and TFs from courses that you liked, and who have some expertise in your proposed field. Tell them what you are interested in, ask if they think it can be done in an existing program, and ask them who else to talk with. Talk to Directors of Undergraduate Studies in departments that might work with your interests. Tell them what you are interested in, ask if they think it can be done in an existing program, and ask them who else to talk with. Make a list of courses that you want to take over your four years at Harvard, and see if they fall into a particular program or not. Start writing your statement of purpose, but continually revise it as you gather more information. Share this with faculty, tutors, and TFs. Work on your “elevator pitch:” you have one minute to tell someone what you study at Harvard, what do you say? Be prepared to find out that your course of study might just work in an existing concentration or joint concentration, a combination of concentration and secondary field, or a path of research including departmental tutorials and senior thesis.