I've been using a Strathmore Toned Gray sketchbook I bought a while ago for practice. It's been a decent surface to work on and the gray color/value of the paper is great for working in black and white. After drawing on newsprint for so long it's nice to be able to have the white charcoal to play with. Here are some recent ones.
It's good to experiment if you ever feel like you're getting into a rut. These demonstration drawings were a good chance for me to try something different. Starting with a charcoal "wash" on the page to create a midtone, I layed out the foundation drawing with vine charcoal. I then used the kneaded eraser to pull out light shapes. It's good to also think of the kneaded eraser as a drawing tool, not just something for correcting mistakes. Finishing touches and any extreme darks are done with charcoal pencil.
Here are some step by step shots of a quick study I did awhile ago. I was trying out some new bristle brushes and wanted to mess around with the brushwork and just see how the paint would go down in general. I was also aiming to keep things simple and avoid over rendering. I find these progressions shots useful to look at after the painting (or drawing) is done to see where things went right or potentially wrong.