Brisket is a tough smoke. My advice is know the internal temps and stay with it until you reach your temp, maybe around 200 IT. Everything else is preference like rub, wood, etc. in my early days of smoking brisket, I repeatedly took it off too soon. Really good but man, was it tough!
Where are you and what are you smoking on?
Good luck and let me know how it goes. I'm cooking for a party of about 40 this weekend myself.