One very important thing to do before getting your hair braided is going to be to get your hair as clean as possible. When you have the braids in it's not going to be as easy to keep your scalp clean so make sure to use your favorite clarifying shampoo just to make sure you've gotten rid of any nasty residue from products leftover on your hair. Another important thing to do is to moisturize your hair very well, it would even be a good idea to do a deep conditioning treatment beforehand.