Agree on what a "good workday" is. This will vary from person to person, as everyone's situation is different, but you need to set an individual track for employees that embraces quality and sustainability over quantity and busyness. Communication is the key to this, but what to communicate can be tricky.
Vacation time for everyone. Set a number of days, at least 20, for each employee, encouraging maximum flexibility. In addition, designate a week during the year when the business will close and employees will get paid time off without needing to use vacation days.
Lead by example. Having positive policies on paper means nothing if people aren't taking advantage of them, and most employees will always be cautious about getting too comfortable until they see no one is judging them for it.