My question involves landlord-tenant law in the State of: California

I sub lease a property I rent to a group of my friends as roommates and my friends and I were looking for a way to obligate everyone to follow rules in the house that we decide democratically at a monthly meeting without using the threat of eviction. I would prefer to base it off a fine system and my roommates are willing to modify the lease as needed to make this work, but I'm not sure how to make this legal or if it's possible to make it legal. We are hoping to put the fines collected from this into buying items that we need for the house.