Northern lights are done with a stylus tool and will be done in several colors.  These take about 25 minutes.

this is going to take about an hour  It's a half sheet of paper and is colored with the "Splash stamp"

this is 8x10 and will take most of the 2 hours
The indian below is another 2 hour scene. 

Tthe purple one is done with Brilliance reinkers and will take about 30 minutes and they will have time to play with a few more maybe.  It's a great technique

The scene below  is a good example of a free form sky and will take about 30 minutes.

 

The two fall scenes below will each take most of the 2 hours.  One is done with the tonal applicator and stamp pads and the other is with the stylus.

The last scene is done by using paper towels as a stencil and gives a very soft look.  It takes about an hour. 

Choose the scenes that you'd like to have the class do.  If these aren't enough to pick from just let me know.