I do traditional line art by hand, unless I need to draw a really long line, which then I'd use a ruler. My ink drawings probably look a lot larger when I upload them, but my hand doesn't actually need to travel very far. For reference, that drawing with the cat and the ghosts is only about 11 cm x 13 cm. The longest line there is slightly under 4 cm, found on the outermost line on the gravestone he's leaning against.

You're true though, it is difficult to get right. I've been doing lines like that off and on for several years, but it's still constantly a hit or a miss getting the line perfect on the first stroke. But the mistakes get hidden since I then thicken the line by going over it a few more times as a part of the style. Referencing the drawing again, the hatching seen within the ears is almost what a single line would look before thickening. (This is the exact pen I use, by the way. I also use their XS and BB sizes at times, but not as often as the regular S size.)

I feel like using a lot of pressure also helps keep things steady too, but of course that ends up hurting after a few minutes, so I also have to consciously remember to loosen up my hand which is... pretty difficult as well, ha ha.

Thank you :]