Beautification
Line weights
Line Weight refers to the thickness or "darkness" of a line. The more force that you apply to your writing utensil, the darker the line will be.
A pencil will have a greater range of light-to-dark shades than a pen but you can create heavier line weights with a pen by going over the same line more than once.
Take out your 3D subtractive work sheet and try drawing lines different line weights. Try with a pencil and different pens if you have them available.
Line weight rule of thumb
If two faces come together and you can see the edge they make, keep it thin.
If you have one edge where you can see one face but not the other, make that edge thicker. We'll call this a "bare" edge.
Put in other words, if you were able to reach your hand around the edge and your hand would disappear, that edge should be made thicker.
Why?
Consider the heavier lines as "Gravity Lines". By adding them, we add more weight to "bare" edges which makes our final object pop more.
Since all of the outer edges of your object will be "bare", you can usually start by outlining the border of your object with heavier line weights.
Most objects have slightly rounded or angled edges which cause them to cast a slight shadow when placed on a surface. If your object is resting on a surface (e.g. the ground or table), add a double thick line weight to edges that come in contact with the surface to show that the object is "grounded".
If you have a sharpie, use that to create a thicker line around the base. If you don't, go over your grounded edges once or twice to thicken and darken the lines.
As you can see, by adding three different line weights to a drawing can make a huge difference.
(thin, thick, double-thick)
Let's add line weight to your 3D subtractive Exercise
On your 3D subtractive work sheet, add different line weights to your forms.
Add thick lines around their borders and "bare" edges
Add double-thick lines to their "grounded edges"