Other skills I reviewed while working with pastel with first graders were:
How do you clean off a pastel when it gets dirty?
Scribble on the back of your paper, until it looks cleaner, repeat as needed.
What do you do it the Pastel isn't working?
It's probably the paper around the pastel that needs to be turn down.
Pastels are very soft and get worn down quicker then crayons.
The softness of the pastel is what makes it an easy tool to mix with.