All the stationery in my shop is drawn from my own holster! Sharing my illustration toolbox with you, these items are my personal favourites, go-tos for myriad illustration and lettering jobs.
 
The Kuretake Brush Pen ('fudenosuke') has a fine brush end and a fat brush end, both tapering to a delicious fine point, The ink is rich and wet and black (so give it a sec to dry).
 
Sweeping, narrowing strokes are possible and these pens are also excellent for lettering, enabling an easy 'signwritten' look. the smaller brush tip is harder, allowing for more even strokes with pressure.
 
ALSO - pen nerds will feel me on this one - both lids pop one into the other, so when you're using one end the loose lid doesn't roll away.
 
Black ink.