I've never had any formal art training. What you are looking at has been achieved through practice and experimentation.
Below is a sampling of my personal artwork prepared in colored pencil, charcoal and pastels.
Additionally, I've expiremented with stencils. Samples of this can be viewed here:
Pencil and charcoal:
Pencil, Charcoal and Pastels:
Unfinished works in pencil/charcoal