A package is a client buying several appointments up front, usually at a discount. What you get is cash now and a client who has a reason to come back. What you give up is margin on every appointment in it, so the discount has to buy something real — commitment, or a course of treatment that only works as a course.
Keep the discount modest. Ten per cent for a course of six is normal; a quarter off is you working a day a month for nothing. If a bigger number is the only thing that sells it, the problem is the price of the individual service, not the package.
Set an expiry that matches the treatment cycle, and say it clearly at the point of sale. Six appointments for a service done every four weeks is a six-month course, not an open-ended credit note. Check your local rules on expiry before you set one — some places restrict it — and be generous about extending for good reason rather than fighting over a week.
Track redemptions on the client's record so both of you can see what is left. The most common failure here is not fraud, it is two people with two different counts and no way to settle it.
Do not let a package erode the cancellation terms. A missed appointment inside a course is still a missed appointment; decide now whether it burns one of the sessions and say so when you sell it.