Expectations are a set up for success. Be specific about what you can and what you cannot, or will not, do. The more specifically you describe your expectations, the more customers (families) will self-select you. Selling becomes superfluous.
Communicating your expectations shows both respect for others and institutional confidence. It says you know what you're doing and that you want families who want to go "all in," too.
What are your learning expectations? What outcomes are you after? What will be required to meet them? What must the school bring the table? The parents? The student?
Develop a student and parent success profile and a risk profile with your faculty. A success profile might address expectations about intellectual curiousity, creativity, motiation, flexibility, self-advocacy. A risk profile would clarify what might jeopardize enrollment or reenrollment, such as low motivation, or excessive emotional dependence. It all depends on your mission.
And don't forget philanthropic expectations. Nothing's worse than the "bait and switch." Enrollment Management and Advancement must work together to educate everyone in the school -- and especially those considering applying -- about the governance and financing of your school. That includes families on tuition assistance. Don't insult them by assuming they can't or don't want to participate in annual giving. Their participation rate may lead to other funding that can enhance your program and affordability.
Get your expectations front and center. No apologies. You'll attract those you want to serve, and they'll appreciate knowing what is expected to create a productive, fun, long-term relationship that will be well worth the investment.