Vree 
"@dinosaurcol":/art/art-resources/post/3446792#post_3446792
Use the Stabilizer tool.
Use the rotate keys to turn the canvas into the right position to do each line with a single arm stroke.
(If you use a portable device like an iPad Pro, then you can just rotate the device.)
The rest is just line weight expertise really.
Know that you can create pseudo-line weight by using more contrast near the line.
There are many reasons to emphasize some lines more then others, but a simple guideline is that line weight follows the same logic as shadows and perspective; so lines that are closer to the viewer in 3D and lines and ones in darker areas get thicker.
..And of course, choose your brush thickness in proportion of the size of the drawing. If it is big then don't be afraid to reallypush thickness where it's needed.
Use the Stabilizer tool.
Use the rotate keys to turn the canvas into the right position to do each line with a single arm stroke.
(If you use a portable device like an iPad Pro, then you can just rotate the device.)
The rest is just line weight expertise really.
Know that you can create pseudo-line weight by using more contrast near the line.
There are many reasons to emphasize some lines more then others, but a simple guideline is that line weight follows the same logic as shadows and perspective; so lines that are closer to the viewer in 3D and lines and ones in darker areas get thicker.
..And of course, choose your brush thickness in proportion of the size of the drawing. If it is big then don't be afraid to reallypush thickness where it's needed.