introduce a different prayer method or devotion each month, such as those listed in the first response. concentrate on LOTH–in fact begin each class with a psalm taken from the appriate day and hour, and explain why and how to pray it. the rosary of course, but going in-depth on the mysteries and their scriptural source, and meditation on those scriptures. you want them to “own” the rosary. Adoration, try if your parish allows to schedule regular times, beginning with no more than 15-20 minutes, for this. beforehand explain what, why and how. and lectio divina, praying with short sections of scripture, usually the Sunday gospels.
above all–my spiritual director (a Jesuit) suggestion–teach the daily examen
once a day, usually at bedtime (but you can practice together at the end of class)
pray to the Holy Spirit for light
recall and review the events of the day
consider the feelings that arise
pray from one of those feelings
praise and thank God for all that happened
express contrition for any sins and failings
make a resolution for tomorrow (not the rest of your life, just tomorrow)
Pray the Our Father.