My favorite material was the oil pastel. I liked these the most because the colors were really bright and cool looking. I also liked this one because it was easy to blend. The layering was a good technique to use.
My second favorite material was the chalk pastel. It was really easy to blend because you can use your finger but other than that i didnt like it that much. I think that this would be the best for large pieces that don't require as much details.
The colored pencils were not that great of a material for me. I didn't like how it blended colors. For something with a lot of details these would be nice since the pencils have smaller tips.