1. Keep it short.
   Students will do 5 minutes per day quite happily. Keep your assignment to a single quiz, at least until you have feedback from the students.
2. Explain the principle to your students.
   They many not be used to homeworks that enforce a daily routine, and some will moan like heck at you that they can’t do it all at once.
3. Demand, and enforce, the first attempt on the first day.
   If the majority of your students leave homework until the last minute of the last day, they will get caught out and may feel you have deliberately trapped them.
4. To track progress, sort results by Attempts.
   Assignments > Results > Results (beta) > click on the top of the Attempts column.
5. To check completion, sort results by Mark.
   Assignments > Results > Results in detail > Sort by Mark, and look for those who scored >80%.

More on Mastery Mode here.