The HELP book series contains a broad range of activities. They are great filler material for current curriculum or better yet, use them as my teachers did to create your own meetings, classes and retreats. There is plenty of commentary and advice on creating prayer and community in each book.
Even the most experienced among us will probably find some surprises as they read along. In the "Prayer" book we found the creative and inexpensive "God Can" prayer which was a fine closing service where we could use all those empty aluminum cans we had collected after lunch at a recent retreat. And for my older teens I will be using the "Post Card Journals" found in the same book.