More pics to practice :-)
Here’s a picture of a hand done on white paper without any shading. Try drawing it, then try sketching your hand in several poses, keeping the detail at about this level. (No shading necessary.)
Then try a drawing of your hand that’s more like the one below (which we drew in class), drawn on grey paper using the white highlighting pencil and shading in graphite. Remember that the fingers are easier if you start from the simple cylindrical shape, then soften and round the lines.
Then try copying the drawing below, also on your grey paper. In this one, white pencil has not been used; instead the lighter areas, like the middle of the nose, are left un-shaded.
Here’s a nice drawing of a mug that I found online, which you might also try copying. It was drawn on white paper. Don’t worry about the shading on the paper outside of the mug, it’s just a digital artifact.
Finally, try drawing the boxes below, then turning them into the four objects shown. Notice how they all start from a simple box. This one can also be done on your plain white paper: