To further protect your pastel drawings from smudging, you can place a sheet of glassine or parchment paper over the completed page before closing the sketchbook. This provides a protective layer between pages, minimizing the chance of smudging. If you're concerned about potential smudging, you...
Use paper towels to keep your oil pastel sticks clean and free of other colors. Oil pastels are a very vibrant medium. Try to keep the individual sticks clean as you work. Moreover, there is a tip for you that you can blend the oil pastels by pre-blending in a palette or directly on the paper...