Have your students double up. One flies while the other sits in the back. Fly somewhere (obviously >50nm) doing maneuvers along the way. Land, students switch, and fly back doing the same. My crew partner and I logged a ton of cross country time doing that at FlightSafety. Not only is it a great way for all of you to build time, it's a great way for them to learn, especially the one sitting in the back. To be able to observe the other make mistakes is incredibly useful.