Rendering
Here's a page for people who really want to learn how to make art. These exercises teach one how to control value and color. This is training for the hand, eye, and mind, so that you can accurately reproduce what you see.
Glue a picture to Bristol board, and extend it in all directions using gouache. Match color, value, line and texture. Mask the edges with tape for clean lines.
The gouache looks much closer to the color of the card than shown in this scan, which has a pattern that affects the color.

This rendering is similar to the color example. Find an illustration or photograph of interest, glue it to Bristol board, and extend it in all directions. The sky in this drawing has too much texture, so Bristol board is not the best choice for this image.

This is the beginning of the rendering of a collage. Match the line, value, color and texture of the original as closely as possible. The element in the lower right was covered after I finished it.
Now we switch to tonal drawing. The top image is a photograph. and the bottom is a tonal drawing done the same size. Draw your lines first, then and the tones, matching the value and texture of the original.