it's important that you find a proper professor or lecturer who would like to take you under his supervision. to this end, you should select a professor or lecture who do the subject you want to do and of course, you'd better know some other things like his personality, whether he is mean to his students or not, if he is a trouble-maker, sth like that. once your target is fixed, contact him and make him want you ,if not very much, by giving out some innovative ideas on the subject or showing him that you are so keen to do phd with him. once you win his heart from the point of view of research, you are not far from success
good luck