Brazilian Jiujitsu is a close contact sport so you never want to be the smelly guy.
Make sure you are wearing clean athletic wear to classes and shower promptly after class.
To ensure you are not scratching and cutting people accidentally make sure your fingernails and toe nails are clipped.
To ensure your own safety and nothing gets caught ALL Jewelry should be removed prior to class
WHEN STEPPING OFF THE MATS MAKE SURE YOU HAVE SHOES ON AND NEVER WEAR SHOES ON THE MAT