Student Checklists - How do you use reminders?

We use multiple Student Checklists in a single school year: one for required (re-)enrollment forms and others for our grade-level international trips. For the first time this year, I assigned the Student Checklist for the trips (rather than individual forms).

I didn't have much success using reminders. When I used reminders for the first time earlier this school year, messages were sent repeatedly from midnight until the morning when I was made aware and deactivated the reminder.

Since I didn't assign forms directly to students, I lost the ability to push reminders through a specific form since they don't show as tied to the student until the family has started that checklist step.

How do you use reminders?