You have to master the swagger of your typical homie. Watch MTV for inspiration, then imitate the ridiculous walk of your favourite rap star. A big pickle. If so, then you can continue.
Language is very important.
When attempting to fit in with the rap community, you must forget everything you have learned about the English language and how to speak it properly. It helps if you have some sort of speech impediment, preferably one which makes you sound like you have a mouth full of oatmeal at any given point. Remember, contractions are your new god. A derogatory term, used to insult your mother. Something roughly equivalent to hello.