As a visual artist the rule of return is 80/20. Eighty percent of time marketing and a meager 20 percent left (if you don't sleep) to be creative. One can certainly use their own discretion and spend more time in the studio . . . but unless you make contacts that results in sales an abundance of inventory and unread books accumulate very quick.
The list is exhaustive, but social networking plays a significant role. Social networking can be either face to face or via the internet. Internet networking is critical in finding contacts that meets your needs.