/// Updated with Closeup of pencil strokes..
Crayola has enough softness for small sample writings, but overall, still too hard to practice with..
Ideally for Expressive pencil writing, 3B hardness provides good line weight variation without being too soft like 5B-6B
The main drawback to pencils, is that you can not perfectly predict where the stroke will end because the core is not of uniform density, it should be but it isn't always.
What happens is, if one segment of the core is too hard, and that is where your stroke ends, that stroke would end Shorter than where you intended, compared to your other strokes.
So if you look at my character for (light blue, 青), the second horizontal stroke ended before the indentation into the paper.
And if we go from a Dense segment into a Loose segment, you get too wide a stroke, Looking at the Vertical stroke on the (orange,橙) character, the middle of the stroke is too wide.
--Of course, since this is HAND writing-- and not Photoshop, Perfection is not the end game..
What you're looking for in a Defining Piece (should you ever attempt one) is an alignment of good odds, and persistence.
Which is why there is an element of GOD in art, because no one person/ artist is in complete control of the outcome.