Take your disciples out one at a time to model evangelism with them. This could be just what your disciples need to take their next major step of growth as campus missionaries. The gocampus.org website has many surveys you can use to initiate with students. Your friendly coach can also get you some great evangelism tools and training. More Summer is a great time to try some creative prayer strategies.
Summer often finds kids staying up late into the nights, without homework.
Try some late-night pizza and prayer nights at students' houses. Meet at 10 pm to pray, have some pizza and watch a movie. That's just one idea. Try bringing your students together for just one regular co-ed discipleship group over the summer. Again, make it fun, and include some food and fun along with the time in the Word.