Have a database to keep track of adoptions. This makes it easier to send out mass emails and to keep track of adoptions: animals that have gone through the shelter, medical information, adoption dates, etc. If your shelter is partnered with any pet insurance company (i.e. Truepanion), try to provide every new owner with discounts through these partnerships. Such as, up to a month of free insurance. This will ease the cost of owning a new pet.