Watch a selection of hip-hop videos and look at pictures of artists and dancers. This will give you an idea of the look you want to create.
Try on some clothing items on the list. Go for slightly baggier clothes than you might normally. A tight vest with a baggy, front-zipping hooded sweater is a standard look.
Accessorize with a hat, jewelry and sunglasses. Try out various combinations and positions of the accessories in front of the mirror.
Coordinate your outfit with other people if you are dancing as a group. In hip-hop it's standard for everyone in the group to be dressed differently rather than in a set costume. However, a certain amount of color coordination is helpful. Make sure that everyone has at least one garment in the same color as everyone else.